Teachers and Examiners (CBSESkillEduction) collaborated to create the JavaScript Class 11 Notes. All the important Information are taken from the NCERT Textbook Web Application (803) class 11.

JavaScript Class 11 Notes

JavaScript Basics

Making interactive web pages is possible with JavaScript, a text-based computer language used both on the client-side and server-side. JavaScript adds interactive aspects to online pages that keep users interested, whereas HTML and CSS are languages that give web pages structure and style.

History of JavaScript

Brendan Eich created JavaScript in 1995 while working at Netscape, and it was originally made available with Netscape 2 in early 1996. LiveScript was the original name; however, to leverage on the success of Sun Microsystems’ Java language, it was changed to JavaScript.

Features of JavaScript

Some specific features of JavaScript are discussed below.

1. Browser Support – All modern browsers support JavaScript natively and accept it as a programming language.
2. Client and Server-Side Support – JavaScript can be used on client side as well as on server side.
3. Functional Programming Language – Variables can be assigned in the functions just like any other programming language. A function has the ability to take another function as a parameter and to return another function.
4. Support for Objects – JavaScript is Object oriented based programming language. JavaScript manages objects and inheritance in easily.
5. Run-Time Environment – JavaScript typically relies through upon a run-time environment to provide objects and methods by which scripts can interact with the outside world.
6. Vendor-specific extensions – The Mozilla Foundation is the official manager of JavaScript, and new language features are regularly added and this features are supported by all browser.
7. Object based features Supported by JavaScript – JavaScript is sometimes referred to as an object-based programming language and supports a number of object-based language characteristics.

Type of Website

There are two types of website –

1. Static Website – A user receives a static website exactly as it was stored. This means that unless the website is completely redesigned or the site administrator changes something directly in the code.
2. Dynamic Website – Facebook and Twitter are two more excellent examples of dynamic websites that produce distinctive, user-specific content. Your feeds are based on friends or accounts you follow on social media platforms like Facebook and Twitter.

Limitations of Static Website

1. It can not be used while changes are being made by the developer so user has to wait until changes are not finished.
2. It has limited functionality.
3. It can cost more to upgrade.
4. It cannot be scaled e.g. if you want add some data then it might be done using separate page.
5. It is less attractive and interactive.

Advantages of JavaScript

1. JavaScript easy to learn.
2. JavaScript can be used for creating dynamic webpage.
3. Event can be used in JavaScript.
4. JavaScript can read and change the contents of an HTML element.
5. JavaScript can be used to validate data of the form before it is submitted to a server. It saves the server from extra processing.
6. JavaScript can be used to create cookies. For example, a JavaScript can be used to store and retrieve information from the visitor’s computer.
7. JavaScript is widely used for developing modern web applications with the capabilities of desktop applications.

Applications/Uses of JavaScript

1. Developing Multimedia Applications – the users can use JavaScript to add multimedia elements.
2. Create Pages Dynamically – based on the user’s choice, JavaScript can generate pages that are customized by the user.  
3. Interact with the user – JavaScript can do some processing of forms and can validate user input when the user submits the form.
4. JavaScript objects are similar to dictionaries – in JavaScript, objects are just a collection of name-value pairs.
5. Extension – JavaScript can be extended for different purposes by supplementing it with additional objects.
6. Client-Side JavaScript – It extends the core language by supplying objects to control a browser (navigator or another web browser) and its document object Model (DOM).
7. Server-Side JavaScript – extends the core language by supplying objects relevant to running JavaScript on a server.

Following steps show how JavaScript works with the web page.

1. When user type address or URL on the browser then a request is transmitted to the server.
2. Server accept the browser request and returns the page to the browser.
3. Browser render the page for HTML tags and display the contents.
4. If page contains the JavaScript code, which are surrounded by <script> and </script>tag generally then JavaScript interpreter handle the code.
5. This code can handle user-initiated event like click on the button, rolling mouse or form submitting etc.
6. It makes the webpage interactive by detecting what is happening on the page and responds it.
7. It can dynamically change the look of web page or contents
8. It can read the cookies and validate them

Web Browser

A browser is an application programme having a graphical user interface for displaying HTML files that is used to surf the World Wide Web and give users access to all of the data there.

Enabling JavaScript in Browsers

JavaScript is supported by all contemporary browsers by default. But occasionally you might need to manually turn on or off this support.

Basic Structure of JavaScript program

Client-side JavaScript code is embedded in HTML code between the either <head></head> tag or <body></body> tag surrounded by <script></script> tag. If code contains the object, functions definitions then it is preferred to add the code between the <head></head> tag. If code have to placed one or multiple scripts in a document then <body></body> tag is used.

<!DOCTYPE>
<html>
<head><title></title></head>
<body >
<script type="text/javascript">
Add javascript code here
</script>
</body>
</html>

JavaScript Syntax

JavaScript syntax is the set of rules that define a structured JavaScript. Here are some tips to remember when writing your first JavaScript program.

• Case Sensitivity – JavaScript is case sensitive i.e., upper case letter and lower-case letter has different meaning.
• Whitespace & Semi Colon – Spaces, tabs, and newlines that are present in JavaScript programmes are ignored by JavaScript.

Comments

Comments are used to make programmes easier to read and are typed with two forward slashes before each word. The interpreter will ignore these comments. In JavaScript, there are two types of comments: single-line comments and multi-line comments.

Single – line comments

// This is comment

Multiline comments

/* This is comment */

Line Break

line breaks are ignored except when it is used within a statement.

JavaScript Code inside the HTML code

<html>
<body>
<script language = “Javascript”> 
Statement 1;
Statement 2;
</script>
</body>
</html>

The write () and writeln() Methods

Without adding a newline at the end, write() method writes a new text to the document. A newline is added at the end of each line that writeln() adds to the page.

The write()Method

<body>
<script type="text/javascript">
document.write("Hello JavaScript");
</script>
</body> 

The writeln() Method

<body>
<script type="text/javascript">
document.writeln("Hello");
document.writeln(" JavaScript");
</script>
</body>

Scripting Language vs Programming Language

• A scripting language does not require compilation before it is run where as code written in programming language first compiled then it is run.
• A code in scripting language is interpreted as it is loaded in the client.
• Error won’t be caught before the script is run while in programming errors are found when it is compiled.
• Errors in JavaScript are handled by browser.

Using internal and external JavaScript files

There are four different place in the HTML document where scripts can be used.

• Body of the page – In this case when page is loaded in the browser then output is displayed as the part of the HTML document.
• Header of the page – In this case code is written in the form of function and referred in the other script in the same page.
• Within HTML tag – When JavaScript is used as a event handler then it work with HTML elements.
• As external file – In this case JavaScript code is written in another file having .js extension. This file is included in a script tag by specifying the file name.

Data Types

The classification of the types of data that a variable or object can store is known as a data type.

There are two type of datatype –

1. Primitive Data Type
2. Non-Primitive Data Type

Primitive Data Type

JavaScript supports three basic data types –

1. Numeric – Numeric type has two type viz. Integer and floating point. Integer is a whole number such as 145, -9 etc. It can be expressed in decimal base(10), octal base (8), hexadecimal (16) of both positive and negative values. Floating point are values with decimal value or fractional value.
2. String – Strings are collection of characters which are enclosed with either single or double quotes.
3. Boolean – This type of data contains only two value i.e. true or false or 0 or 1. When these values are compared then true value is taken as 1 and false value is taken as 0.

Composite Data Types (Non-Primitive Data Type)

When a data type declares several identical or dissimilar data under a single variable declaration, or when the data type includes multiple values grouped together, the data type is referred to as a composite data type. The three primary categories of composite data types are listed below. Array. Function.

Variables

Anything that can change is considered variable. A variable saves the data value in JavaScript and allows for future data value changes. If you want to declare a variable in JavaScript, use the reserved term var.

• Variables can be thought of as named containers in the computer’s memory. You can place data in these containers and refer to the value using the name.
• A variable consists of an identifier, a scope and a specific data typ
• An Identifier is the name of a variable.

Usefulness of Variable

• When code is written they can be used in place of unknown value.
• When script is written or updated then it saves the time
• Then clearer the purpose of code because you can give the meaningful name which make the code easy to read.

Variable Naming Convention

JavaScript has some rules when we give the name to the variable.

• Case Sensitivity – JavaScript variables are case sensitive.
• Use Valid Characters – A variable must begin with underscore or letter only. All other characters are invalid to start the variable name. Variable must not contains blank spaces.
• Avoid Reserved Words – Reserved words are the special words which has specific meaning in JavaScript.

Variable Declaration and Initialization

• Variables in JavaScript can be defined using the keyword var.
• The equal to (=) sign is used to assign a value to a variable.
• Note that var is the keyword in JavaScript.
• Users can either, separately declare the variable and then assign values to it or straight-away declare and initialize the variables.

Variable Scope

The scope of a variable refers to the area of a program in which it can be accessed. Variables have two types of scopes – global scope and local scope.

• Global Scope – Outside of a function, global variables are defined to be accessible throughout the entire programme.
• Local Scope – Using the var keyword, local variables are kept in a function and can only be used inside the confines of that function.

Operators

An operator is a symbol that is used to perform an operation. in this section we will learn how to use JavaScript operators.

Assignment Operators

Assignment operators help in assigning values to a variable. the following are the example –

=, +=, -=, *=, /=, %=

Arithmetic Operators

There are following arithmetic operators supported by JavaScript language –

+, -, *, /, ++, —

Comparison Operators

There are following comparison operators supported by JavaScript language.

==, !=, >, <, >=, <=

Logical Operators

There are following logical operators supported by JavaScript language.

&&, ||, !

Bitwise Operators

There are following bitwise operators supported by JavaScript language.

&, |, ^, ~, <<, >>, >>>

Built-in Functions/Object for Numerical Calculation

Basic Math Operation

isNaN() – NaN stands for “Not-a-Number” in JavaScript. This method checks whether passing argument is a number or not. It returns true or false value as a result.

document.write( isNaN(4) ) // will return false.
document.write( isNaN(“4”) ) // will return false.
document.write( isNaN(“four”) ) // will return true.

valueOf() – This method return a number of a given variable. For example
var x =345;
x.valueOf() // will return 345;

Math.round(x) – It returns the rounded value of passing number to its nearest integer. For example:
Math.round(6.7) //returns 7
Math.round(6.4) //returns 6

Math.pow(x,y) – It returns the power of x based on y. For example:
Math.pow(3,4) //returns 81

Math.sqrt(x) – It returns the square root of x. For example:
Maths.sqrt(81) //returns 9

Math.ceil(x) – It returns the greater or equal to integer value of x.
Math.ceil(6.4) //returns 7

Math.floor(x) – It returns the less or equal to integer value of x

Math.floor(6.4) //returns 6
Math.ceil(3.9) //returns 3

Basic String Operations

Length() – It returns the length of a string including white space(s). For example
var str = “Hello javaScript”;
document.write(str.length); // it returns the 16.

Search() – It returns the starting location of passing string otherwise returns -1.
var str = “This is my first script in JavaScript”
str.search(“script”); //returns 17

Substring() – It extract the substring by taking the starting and ending position as argument. You can omit ending position then it will extract the string from starting position to end of the string.
var str = “This is my first script in JavaScript”
str.substring(7,16) // returns “my first” as substring

Data Type Conversion

The process of transforming data from one type to another is known as type conversion. Changing data from a String to a Number, for instance. In JavaScript, there are two types of type conversion. Automatic type conversion is known as implicit conversion. Manual type conversion is known as explicit conversion.

Implicit Type Conversion

JavaScript occasionally automatically changes one data type to another (to the right type). Implicit conversion describes this situation.

Example 1 – document.write("3" + "1");

Output – 4

Example 2 – document.write(3 + "1");

Output – 4

In example 1, both value having string type but due to Implicit Type Conversion value automatically converted in numerical value.

Explicit Type Conversion

This type of conversion is done by developer by using the inbuilt method of type conversions.

• Number() – This method is used to convert any type to number type.

Number (“40”) convert string value “40” to 40.

Number (null) convert null to 0

• parseInt() – This method returns the integer value by accepting two argument.

parseInt (“10”) returns 10
parseInt (“40.33”) returns 40

• parseFloat() – This method returns the integer value by accepting one string argument.

parseFloat(“23”) returns 23
parseFloat(“23.55”) returns 23.55

• eval() – This method accept the JavaScript expression as an string argument. It then evaluates the expression and return the result after execution. If no result is obtained the it returns undefined as a result. For example:

eval (“ 8*4/2”) returns 16 as result

Converting String

String() method is used to convert any type to string value whereas possible by accepting one argument.

string (40) converted to “40”

Converting Boolean

Boolean() method convert any type to Boolean type which is supported.

Boolean(25) returns true.

Display method in JavaScript

We have seen document object methods which are used to display the content on the web page. Let see some other methods for display text in JavaScript.

Alert() Dialog Box

The alert message is displayed in the alert dialogue, which also provides a yes-or-no response. Your response determines the next step that is taken once the alert dialogue has displayed its message to warn you.

alert(“You want to continue….”);

Prompt() Dialog Box

The user is prompted for input in a dialogue box by the prompt() method. If the user selects “OK,” the prompt() method returns the input value; otherwise, it returns null.

prompt(“Enter your name”); – By default prompt store only string value

parseInt(prompt(“Enter Number”); – Now the value will be convert to integer value.

Confirm() Dialog Box

Most often, a confirmation dialogue box is used to obtain the user’s approval for any option. A dialogue box with the buttons OK and Cancel is displayed.

var ans =confirm(“Are you really want to cancel the order?”);

Decision Making using if and switch

Conditional Statements

• If else Statement

Conditional statements are supported by if and else described below –

if(condition)
{
True Statement;
}
else
{
False Statement;
}

• Switch statement

The switch statement is used to select one of many blocks of the code to be executed.

switch (expression){
case n:
code block
break;
case n:
code block
break;
default:
default code block
} 

Looping Structure

For Loop

The for loop is best suited when you already know the number of times the statements should be executed. the loop executes until the condition becomes false.

for(initialization; condition; increment)
{//statements } 

While Loop

The While loop is another commonly used loop in JavaScript. the purpose of the while loop is to execute a block of statements over and over again until the condition fails.

var i = 1;
while (i < 10) {
alert(i);
i = i + 1;
}

Do-while Loop

This is another kind of loop and different from the for loop and the while loop. this loop will execute the statement at least once that is the statements inside the loop will always get executed at least once, even if the condition is false.

var i = 1;
do {
alert(i);
i = i + 1;
} while (i<10);

Break and Continue

The break statement is very useful to break the loop in the middle of an execution. the break statement can also be used to jump out of the loop. the break statement breaks the loop and continues executing the code after the loop.

for (i = 0; i < 5; i++)
{
if( i==3)
break;
document.write("Hello Life! You are so Good" +"<br>");
} 

Employability Skills Class 11 Notes

• Unit 1 : Communication Skills – III
• Unit 2 : Self-Management Skills – III
• Unit 3 : Information and Communication Technology Skills – III
• Unit 4 : Entrepreneurial Skills – III
• Unit 5 : Green Skills – III

Employability Skills Class 11 MCQ

• Unit 1 : Communication Skills – III
• Unit 2 : Self-Management Skills – III
• Unit 3 : Information and Communication Technology Skills – III
• Unit 4 : Entrepreneurial Skills – III
• Unit 5 : Green Skills – III

Employability Skills Class 11 Questions and Answers

• Unit 1 : Communication Skills – III
• Unit 2 : Self-Management Skills – III
• Unit 3 : Information and Communication Technology Skills – III
• Unit 4 : Entrepreneurial Skills – III
• Unit 5 : Green Skills – III

Web Application Class 11 Notes

• Networking and Internet Class 11 Notes
• Website Development using HTML and CSS Class 11 Notes
• Multimedia Class 11 Notes
• JavaScript Class 11 Notes

Web Application Class 11 MCQ

• Network and Internet Class 11 MCQ
• Web Designing with HTML and CSS MCQ Questions
• GIMP Class 11 MCQ Questions
• JavaScript Class 11 MCQ

Web Application Class 11 Questions and Answers

• Network and Internet Class 11 Questions and Answers
• Web Development using HTML and CSS Questions and Answers
• GIMP Class 11 Questions and Answers
• JavaScript Class 11 Questions and Answers

Teachers and Examiners (CBSESkillEduction) collaborated to create the Multimedia Class 11 Notes. All the important Information are taken from the NCERT Textbook Web Application (803) class 11.

Multimedia Class 11 Notes

Multimedia is the result of combining the words multi (meaning more than one) and media (meaning a mode of transmitting information). Multimedia thus refers to the integrated use of multiple contemporaneous media. The following media types could be a part of it – 

• Text
• Graphics and Images
• Audio
• Video
• Animation

Attractions in using Multimedia Technology

• Yielding Simplicity and Ease of use
• Interactive Interface
• Better Understanding of the Content
• Cost Effectiveness
• Having Fun element

Various open source tools for image editing

1. GIMP (Windows, Linux, OSX)
2. Fotor (Windows, OSX, Android, Online)
3. Fooflexer (Online)
4. Snapseed (Android, iOS)
5. Paint.net (Windows)
6. Autodesk Pixlr (Windows, OSX, iOS, Android, Online)
7. Picasa (Google’s photo manager: Windows, OSX)

GIMP as a Multimedia Tool for Image Manipulation

GIMP is an open source software suite to create, edit, enhance and manipulate images. The first version of the GIMP (x0.54) was written by Peter Mattis and Spencer Kimball, students at Berkeley, back in 1996.

Few attractive features of GIMP

• Software suite of painting and drawing tools with various brushes, a pencil, an airbrush, cloning, etc.
• Paint tools supporting high-quality anti-aliasing.
• Multiple Layers and channels for image manipulations.
• Transformation tools including rotate, scale, shear and flip.
• A procedural database for calling internal GIMP functions from external programs such as Script-Fu and Python-Fu.
• Advanced scripting capabilities.
• Multiple undo or redo effects on images if sufficient disk space available.
• Support for various file formats, including GIF, JPEG, PNG, TIFF, TGA, PS, PDF, PCX, BMP, XPM, and MPEG etc.
• A variety of Selection tools, including rectangle, ellipse, intelligent scissors etc.
• Plug-ins supporting easy addition of new file formats and filters.

GIMP Tool Box

GIMP has an encircling tool suite, to perform a variety of image manipulations, selection and enhancement operations.

Selection Tool

With the help of selection tools, it is possible to pick out certain areas or regions of an image’s current layer for manipulation. Any action taken by the user after making a selection will only affect the region that the selection covers.

− Clicking tool icon in the Toolbox
− Tool Menu Bar (Tools Selection Tools Rectangle Select/or any other select)
− Shortcut keyboard key

The selection tools are listed in Table below:

Tool Options

The most commonly associated features with selection tools are modes, antialiasing and feather edges.

The way that a new selection interacts with an existing selection is controlled by the mode. Replace, Add, Subtract, and Intersection are some of the modes that are available with Selection tools.

• Replace mode will cause existing selection is replaced by new selection.
• Add mode will cause new selection to be added to existing selection
• Subtract mode will remove the new selection from existing selection.
• Intersection mode will overlap the new selection with existing selection i.e. final selection contains the area common to both the selections.

Key identifiers with Modes in Selection Tools

Using Selection Tools

The steps to execute selection tools on images are listed below –
Step 1 : Click “File” then “Open” to open an image from the computer drive.
Step 2 : Click on the selection tool icon in GIMP’s toolbox. Alternatively, the selection tool could be chosen by selecting “Tools” from the program’s menu, and then clicking the desired “Selection tools”. The chosen tool is dragged over the current image to select the desired area.
Step 3 : Once the area has been selected, a boundary (rectangle/ellipse/marquee/ etc.) is visible around the selected portion.
Step 4 : Selected portion is used for further image manipulations and other operations.

Rectangle Select

The most popular tool for selecting rectangular sections of the active layer is the rectangle, which builds rectangular or square selection frames around the image with tiny squares in each corner.

Ellipse Select

By drawing the circular or elliptical boundaries on an image, the Ellipse Selection tool is used to select circular or elliptical sections.

Free Select

In the picture window, the Free Select (Lasso) tool uses mouse clicking and dragging to trace the selection shape. Release of the mouse button completes the action.

Intelligent Scissors

Intelligent Scissors automatically picks a portion of an image. It takes design cues from path and lasso tool functionalities.
The boundary around the region to be selected is made by connecting the nodes or anchor points that were mouse-clicked at the edges.

Foreground Select

By removing foreground from the current image, it performs selection. When the foreground and background have vividly different colour saturations, this tool performs better. In essence, it combines two distinct tools:
Use the lasso tool to choose a foreground region (similar to the Free Select tool) Use the paintbrush tool to paint over a selection to show the colour in the foreground.

Fuzzy Select

A tool called Fuzzy Select uses colours. The “magic wand” technique, also known as fuzzy selection, is used to choose portions of an image that have a similar colour component. The basis for this tool’s usefulness is its analysis of the RGB colour components of the pixels it clicks on. Selecting the proper beginning place is crucial.

By Color Select

Regardless of their placement in the image, all pixels with identical colour components are taken into account when making a selection based on colour. In contrast to the fuzzy tool, the related pixels are automatically identified even if they are obscured by other colours.

PAINT TOOLS

Additionally, you can choose a paint tool from the Paint Tool tab or by choosing an icon in the toolbox. Keyboard shortcuts are also an option. Table Paint Tools contains a list of these tools’ features. The fundamental brushes and colour selection options for the Paint tools are the same for both the normal palette and a gradient. There are numerous painting modes supported by the Paint tools.

Smudging and Stamping for images

Smudge Tool

To smudge colour pixels on a chosen layer, use the smudge tool. Smudging is used to blur the image, hide objects, ease colour transitions, and create textures. smudge When a smudge tool is used on a picture, it chooses a colour from the palette and combines it with the other colours already there.

Clone Tool

The clone tool is used to duplicate the chosen areas of an image or to copy the pixels from those portions to a destination area that the user wants to cover. It copies from a source image using the currently active brush. It can be used for many different things, but one of its most well-known uses is to fix digital photos or photographs by adding painted pixels from a chosen location.

Transform Tools

The display of a picture or a specific aspect inside an image is frequently changed via transform tools.
There are nine of these tools, and each one offers a wide range of functionality and tool possibilities.

Edge Detection Filters

GIMP also renders edge-detecting filters for searching boundaries between various colors of an image based on gradient calculus methods.

Employability Skills Class 11 Notes

• Unit 1 : Communication Skills – III
• Unit 2 : Self-Management Skills – III
• Unit 3 : Information and Communication Technology Skills – III
• Unit 4 : Entrepreneurial Skills – III
• Unit 5 : Green Skills – III

Employability Skills Class 11 MCQ

• Unit 1 : Communication Skills – III
• Unit 2 : Self-Management Skills – III
• Unit 3 : Information and Communication Technology Skills – III
• Unit 4 : Entrepreneurial Skills – III
• Unit 5 : Green Skills – III

Employability Skills Class 11 Questions and Answers

• Unit 1 : Communication Skills – III
• Unit 2 : Self-Management Skills – III
• Unit 3 : Information and Communication Technology Skills – III
• Unit 4 : Entrepreneurial Skills – III
• Unit 5 : Green Skills – III

Web Application Class 11 Notes

• Networking and Internet Class 11 Notes
• Website Development using HTML and CSS Class 11 Notes
• Multimedia Class 11 Notes
• JavaScript Class 11 Notes

Web Application Class 11 MCQ

• Network and Internet Class 11 MCQ
• Web Designing with HTML and CSS MCQ Questions
• GIMP Class 11 MCQ Questions
• JavaScript Class 11 MCQ

Web Application Class 11 Questions and Answers

• Network and Internet Class 11 Questions and Answers
• Web Development using HTML and CSS Questions and Answers
• GIMP Class 11 Questions and Answers
• JavaScript Class 11 Questions and Answers

Teachers and Examiners (CBSESkillEduction) collaborated to create the Networking and Internet Class 11 Notes. All the important Information are taken from the NCERT Textbook Web Application (803) class 11.

Networking and Internet Class 11 Notes

Bell proposed the idea of communication through telephone lines in 1876, which led to the creation of the Public Switched Telephone Network (PSTN) in 1877. The US Department of Defense became aware of the necessity of creating a network by joining together geographically dispersed research computers. As a result, the Advanced Research Projects Agency Network (ARPANET) was created in 1969. Digital packet switching was a technology used by ARPANET. Its use was first limited to noncommercial endeavor’s like the military and research. TCP/IP (Transmission Control Protocol/Internet Protocol) was created in 1970 in response to the need for communication among multiple heterogeneous networks. In addition to various smaller networks, NSF created NSFNET, a sizable network, in 1984.

Basic Networking Concepts

A network is any collection of independent computers that communicate with one another over a shared network medium.

Need for Networking

Resource Sharing – Sharing hardware and software resources is made possible by networking computers. Printer, scanner, and memory are three examples…

Communication – Information sharing between network nodes is facilitated by connecting computers through a network. For instance, because the printer is linked to every network node, any of the computer systems can send data to any of the three computer systems or to the printer.

Access to remote databases – A regular individual can easily access any remote database, such as airline bookings, and book tickets.

Requirements of a network

1. At least two computers
2. Network Interface Cards (NIC) A connection medium, usually a wire or cable, although wireless communication between networked computers and peripherals is also possible.
3. Network Operating system soft Novell NetWare, Unix and Linux

Network Terminologies

Nodes (Workstations) – Any network device that can receive and deliver data from one endpoint to another using a connection point is known as node, such as a router, printer, or switch.

Server – The server is a computer that enables the exchange of data, software, and hardware resources through a network. There are two types of Server –

Dedicated Server – These are generally used on big network installations where one computer is reserved for the dedicated task.

Non – dedicated Server – A workstation can function as both a client and a server in small networks.

Network Interface Unit – Each workstation and the server have a network interface unit attached to them, which aids in establishing connection between the server and workstations.

Switching Techniques

In order to efficiently send data across the network, switching mechanisms are used. Circuit switching and packet switching are the two switching methods now used to enable communication between two computers on a network.

Circuit switching – Circuit switching is a style of network design in which a physical path is acquired and allocated for the duration of a dedicated connection between two endpoints in the network. Circuit switching is used in standard voice phone service. The duration of a call is when this reserved circuit is utilised.

Packet switching – Small data packets are sent between different networks using packet switching. These data “packets” or “chunks” enable quicker, more effective data transport. When a user transfers a file over a network, it frequently travels in smaller data packets rather than all at once.

Data communication terminologies

Channel – The medium over which a message is transmitted from one location to another is known as a communication channel. It is a channel that allows data to be transmitted between distant devices, to put it simply. The complete physical medium, such as a phone line, optical fibre, coaxial cable, or twisted pair wire, may be referred to as a communication channel.

Bandwidth – The most data that can be sent through an internet connection in a specific amount of time is known as Bandwidth. It is actually the amount of data that can be delivered across a connection in a given amount of time, measured in megabits per second (Mbps). Modal.

The data transfer rate – The speed at which a device or network component can send and receive data is referred to as a data transfer rate (DTR).

Network Types

On the basis of geographical span, the network can be broadly categorized as PAN, LAN, MAN, and WAN.

Personal Area Network – A personal area network (PAN) is a type of computer network designed to connect computers and other devices that are near to a single user. Personal computers, printers, fax machines, telephones, PDAs, scanners are the example of Personal Area Network.

Local Area Network – When a network is established within a restricted geographic area, it is referred to as a local network. Private networks with a radius of up to 1 km. They are typically established on a campus or in a building. LANs function at speeds between 10 Mbps and 1 Gbps.

Metropolitan Area Network – A single organisation, a large group of people, or many different people or organisations may own a metropolitan area network (MAN). These networks, which have a radius of up to 50 km, are used to create connections within cities.

Wide Area Network – The WAN (wide area network) covers roughly 1000 km. They are useful for linking isolated places and for long-distance communication. They create connections inside a nation or continent.

Networking Concepts – II

A transmission medium is a channel of transmission used to send signals carrying data from one node to another. The data is converted into an appropriate form for transmission on the medium via a signal.

Guided Medium – Physical conductors like twisted pairs, coaxial cable, and fibre optics are referred to by this phrase. The signal travels as voltage and current in coaxial and twisted pair cable but as light in optical fibre.

Unguided Medium – Electrons are used by the unguided medium instead of a physical conductor. Microwave, radio waves, and infrared are a few examples of unguided media.

Network Topologies

Network topology refers to a network’s configuration of notes. Broadly speaking, there are two different topologies: broadcast and point-to-point.

Broadcast Topology – Broadcasting information typically refers to sending it to numerous receivers. In the same way that a radio station sends a signal to its many listeners, a TV provider broadcasts a signal to digital TV customers.

Point – to – point Topology – The simplest topology is point to point, which uses a shared link to directly connect two nodes. Transmission between such two nodes is limited to using the total available bandwidth of the common link.

Bus Topology

Bus topology, often called line topology, is a type of network topology in which each device is connected to the network by a single coaxial or RJ-45 network wire.

Ring Topology

In a ring topology, every device is connected via a wire that forms a ring. The intended recipient of the message is reached by way of a one-way transmission of the intended message. Device addition and deletion, as well as fault isolation and detection, are simple processes.

Star Topology

All of the devices in a star topology are linked to a central controller called a hub since communication between any two devices occurs through the hub. Installation and configuration of the Star network are simple. Furthermore, fault isolation and detection are simple.

Mesh Topology

Every node in the network is connected to every other node thanks to mesh topology. The topology offers secure data transport without any triffic issues because to dedicated point-to-point connections between every feasible pair of nodes.

Tree Topology

A hybrid topology that combines bus and star topologies is called tree topology.
In a bus topology, backbone cable functions as the tree’s stem, while star networks (and even individual nodes) are connected to the primary tree by star cables.

Network Devices

Creation of a network requires various network devices, each of which plays a specific role in the network.

Repeater – A signal may weaken and degrade with increased distance. In order for the input signal to return to its original form and cover a greater distance, a repeater is required.

Hub – A hub is a computer device’s connection point where data from various ways converge before being delivered in various directions to the appropriate devices. By stopping specific data packets from travelling to a destination, a hub can also function as a switch.

Bridge – A bridge is a multiport network interface used to connect two or more LANs, sometimes at differing speeds. Therefore, a bridge can be used to combine smaller LANs to create a larger LAN.

Switch – Switches are used to connect individual nodes in the network with one another, as opposed to bridges, which join two or more LAN segments. Each node in the network is linked to a different switch port.

Router – Switches are used to connect individual nodes in the network with one another, as opposed to bridges, which join two or more LAN segments. Each node in the network is linked to a different switch port.

Gateway – A gateway enables communication across networks based on various protocol systems. Data from one network that uses one protocol is translated to the outgoing network’s protocol before being forwarded. As a result, a gateway can be compared to a router that has software for protocol conversion.

RJ-45 – RJ-45, the abbreviation for Registered Jack, is used to link computers on LANs, particularly Ethernet LANs. RJ connectors resemble RJ equipment in appearance, however they are a little wider.

Wi-Fi Card – Wi-Fi cards are small and portable cards that allow your desktop or laptop computer to connect to the internet through a wireless network.

Network Protocols

Transmission Control Protocol (TCP) – For communication via a network, TCP is a well-known communication protocol. Any communication is split up into a number of packets that are transferred from the source to the destination, where they are reassembled.

Internet Protocol (IP) – The process or technique used to transmit data from one computer to another via the internet is known as Internet Protocol (IP). Every computer on the internet, referred to as a host, has at least one IP address that distinguishes it from every other computer there.

Point-to-Point Protocol – One computer system is connected to another using the TCP/IP protocol known as Point-to-Point Protocol (PPP). PPP is a protocol that computers use to communicate across landlines and the Internet. When two systems are physically linked by a phone line, a PPP connection is created.

HyperText Transfer Protocol (HTTP) – Resources are transferred across the internet between client devices and servers via the HTTP protocol. Client devices ask servers for the resources required to load a web page; the servers respond by sending the client devices the requested resources.

File Transfer Protocol (FTP) – The file transfer protocol is a method for downloading, uploading, and moving files between computer systems and across the internet. File transfers between computers or via the cloud are made possible through FTP.

Simple mail transport Protocol (SMTP) – Outgoing email can be sent and distributed via SMTP. The SMTP protocol is dependable and simple to set up. Either messages reach their intended destination or an error message notifying them of the situation.

Post office Protocol (POP) – Incoming emails can be received via POP3. A popular way of getting email that receives and retains email for a person until they pick it up is known as Post Office Protocol 3 (POP3).

Telnet – The primary internet protocol for connecting to distant machines is telnet. It enables TCP/IP network connections to remote computers.

Internet Relay Chat (IRC) – IRC protocol is used for chatting. The message is passed between clients via the IRC server.

Voice over Internet Protocol (VoIP) – Instead of using a public switched telephone network, it makes it possible to transport voice over a packet switched network. Phone calls can be made utilizing a regular internet connection by using VOIP software. Today, there are three major types of VoIP service that are frequently used – ATA, IP phones, Computer-to-computer.

Web Architecture

Before a website is designed, developed, and launched, its technical, functional, and aesthetic components are planned and designed as part of its website architecture. It is a tool that website designers and developers use to create websites.

Types of web architectures

Client-server model

Clients and servers made up the first two tiers of the web’s architecture. The functions and services that the system was designed to provide were shared by clients and servers. For instance, the client might ask the server for a service, and the server would then respond by offering the requested service.

Three-tier model

Three-tier architectures have an application logic that handles data processing and permits some interaction between the client and the server. For instance, a database server is just used for data storage, whereas an application server can process data. This allows for the dynamic loading and saving of content. The client’s behavior is frequently dictated by the scripting language JavaScript.

Service-oriented architectures (SOA)

The web is being utilized to connect internationally dispersed IT structures. The client-server model is much simpler than the complexity of modern IT and online applications. Business processes can be automated using SOAs by the systems involved talking with one another, sometimes without human intervention, and carrying out specific duties. Online marketplaces, e-commerce, e-learning, online banking, and business intelligence applications are a few examples.

MAC Address

Each device on a network has a unique identity known as a Media Access Control address (MAC address). It is primarily assigned by the manufacturer. They are frequently located on the network interface controller (NIC) card of a device.

IP Address

Every computer in a network has an additional distinctive identification code called an IP Address. The four bytes (or 32 bits) that make up an IP address can range in value from 0 to 255. A typical IP address appears as follows:
59.177.134.72

Domain Name

Consequently, we may use a computer’s IP address whenever we need to speak with it online. However, it is virtually difficult for anyone to keep track of all the computers’ IP addresses with whom they might need to interact. As a result, a system that gives names to some computers (web servers) and keeps a database of these names and associated IP addresses has been created.

Generic Domain Names:
·com – commercial business
·edu – Educational institutions
·gov – Government agencies
·mil – Military
·net – Network organizations
·org – Organizations (nonprofit)

Country Specific Domain Names:
.in – India
·au – Australia
·ca – Canada
.ch – China
.nz – New Zealand
.pk – Pakistan
.jp – Japan
.us – United States of America

Domain Name Resolution

The process of translating domain names into IP addresses is known as domain resolution. The DNS server is responsible for domain name resolution. Domain resolution is also referred to as domain pointing, server configuration, reverse IP registration, and other similar terms.

Network Threats and Security Measures

Malwares

Malicious software (programmes) that are intended to harm the system or to gain unauthorised access to it, interfere with regular system performance, or prevent authorised users from using computing resources are referred to as malware. Malware includes viruses, worms, and Trojan horses.

Virus – A virus is a piece of software code that can damage your computer by corrupting or overwriting system data. A computer virus behaves similarly to viruses that impact human bodies by replicating and harming cells.

Worm – A worm is frequently acquired via a network, and it floods the hard disc by automatically producing several copies of itself there. It causes network congestion when a worm is received as an email attachment and automatically forwarded to the recipients.

Trojan Horse – A Trojan Horse is a piece of code that makes the system seem desirable and useful but actually does the opposite. A Trojan horse can integrate with a reliable programme. For instance, it might be included with any game that you download from the Internet.

Eavesdropping – The act of secretly or covertly listening to another person’s private discussion or communications without that person’s agreement is known as eavesdropping. Telephone lines, cell phone networks, email, and instant messaging are all used for eavesdropping.

Denial of Service – A denial-of-service attack (DoS attack) is a cyber-attack in which the machine or network resource becomes unavailable to its users by temporarily or indefinitely
disrupting services.

Phishing – The practice of stealing a user’s personal information through fraudulent mail is known as phishing. These emails either include embedded forms that request personal information from you or include links to web pages that might ask you for it. There may be attempts to steal passwords, bank account numbers, debit/credit card numbers, and other sensitive information.

Cyber Crime

Cybercrimes are the crimes related to the misuse of computers or the Internet such as theft, fraud, and forgery. Some of these crimes are mentioned below

• Sending spam mails to uninterested recipients.
• Hacking someone’s account or system.
• Stealing someone’s personal information through phishing
• Hosting a site carrying lots of malwares or being a source for spreading them.
• Harassing someone through mails, messages or social networking.
• Posting offensive content on any site or sending it to anyone.
• Defaming someone using the Internet.
• Forging someone’s digital signatures
• Indulging in fraudulent financial transaction
• Providing misleading information to clients/ general public through use of Internet resources
• Intellectual Property theft
• Illegal downloads, plagiarism

Network Security Tools and Services

Firewalls – An enterprise, home, or individual’s internal network is protected by a firewall from malicious traffic coming from other networks.

Antivirus – Antivirus software works to safeguard your computer from harmful and potentially undesirable programmes. It is in charge of looking for and deleting these malicious programmes in order to keep the system safe.

Password managers – A password manager is a piece of software that aids in organising and storing passwords.

Protective Measures while accessing Internet

• Never click on a suspicious link specified on a web page or send through a mail for which you are not sure about its authenticity.
• Make sure that passwords are strong and are changed frequently.
• Never disclose personal information such as date of birth, home address, personal phone number, account details, passwords, credit and debit card details, work history details.
• Report phishing issues to the concerned authorities or at cybercrime.gov.in. In case of unsolicited mails, mark them as spam mails.
• Secure HyperText Transfer Protocol (HTTPs) is a secure version used for communication between client and host on the Internet.
• Ensure that the web browser being used for accessing the web is updated and is secure.
• Beware before spreading any kind of a rumor as it may be treated as a cybercrime.
• If someone is harassing or threatening you, take a snapshot of it as a proof, and block the person. Also, report the incident to the site administrator
• Use updated antivirus and firewall, secure browsing, and password management techniques.

Cyber Law

Cyber laws are the laws for systematic use of e-resources, for example, e-business, and serve as a measure against illegal cyber-crime.

Cyber offenses under IT Act

• Tampering with computer source documents – Section 65
• Hacking -Section 66
• Publishing of information which is obscene in electronic form -Section 67

Intellectual property rights (IPR) Issues

Intellectual property rights are the rights given to an individual over the invention of their own.

Patent – An invention is a product or a technique that, in general, offers a new way of doing something or presents a new technical solution to a problem. A patent is an exclusive right awarded for an invention. Technical details concerning the innovation must be made public in a patent application in order to obtain one.

Trademark – A trademark is characterized as a name, a different sign, or a tool used to distinguish a good or a service. A particular person or business produces or offers the goods or service.

Copyright – A written document is referred to as having copyright. The violation of copyrights may result in legal action. The following type of work is eligible for copyright protection. written works any accompanying words for musical works.

Employability Skills Class 11 Notes

• Unit 1 : Communication Skills – III
• Unit 2 : Self-Management Skills – III
• Unit 3 : Information and Communication Technology Skills – III
• Unit 4 : Entrepreneurial Skills – III
• Unit 5 : Green Skills – III

Employability Skills Class 11 MCQ

• Unit 1 : Communication Skills – III
• Unit 2 : Self-Management Skills – III
• Unit 3 : Information and Communication Technology Skills – III
• Unit 4 : Entrepreneurial Skills – III
• Unit 5 : Green Skills – III

Employability Skills Class 11 Questions and Answers

• Unit 1 : Communication Skills – III
• Unit 2 : Self-Management Skills – III
• Unit 3 : Information and Communication Technology Skills – III
• Unit 4 : Entrepreneurial Skills – III
• Unit 5 : Green Skills – III

Web Application Class 11 Notes

• Networking and Internet Class 11 Notes
• Website Development using HTML and CSS Class 11 Notes
• Multimedia Class 11 Notes
• JavaScript Class 11 Notes

Web Application Class 11 MCQ

• Network and Internet Class 11 MCQ
• Web Designing with HTML and CSS MCQ Questions
• GIMP Class 11 MCQ Questions
• JavaScript Class 11 MCQ

Web Application Class 11 Questions and Answers

• Network and Internet Class 11 Questions and Answers
• Web Development using HTML and CSS Questions and Answers
• GIMP Class 11 Questions and Answers
• JavaScript Class 11 Questions and Answers