Touchpad Computer Applications Class 10

UNIT-1 NETWORKING

1

NETWORKING

In the recent past, people have been applying different methods of communication to transfer information or to share knowledge amongst each other through postage, telephone, couriers, meeting, news room, training, conference, etc.

But, with the invention of computers, extraordinary development has taken place in the field of communication and now sharing of information has become quicker and easier, irrespective of the geographical location of recipients around the globe, thereby replacing the traditional media of communication.

Internet

In the present era, we commonly use e-mail, web chatting, e-learning, video conferencing, newsgroup, e-commerce, e-reservation, etc. for our day to day tasks.

All such terms must be making you curious to explore more about them. These are actually based on sharing information among millions of computers around the globe which is commonly termed as ‘INTERNET’.

Internet is an interconnected Wide Area Network (WAN) of millions of computers that are linked together around the world. With Internet we can share information in the form of data, graphics, sound, software, text, etc. instantly as and when required with a minimum overhead cost.

Internet is also referred to as Network of Networks. It establishes a high level of connectivity which has resulted into an unparallel degree of fastest, easiest and the cheapest ways to transfer or share data and information around the globe. It provides access to communication services and information resources to millions of users around the globe, round the clock.

Apart from one to one communication, it has led people, organizations, government bodies, etc. to flash information about themselves through their websites which can be viewed by any person across the world.

History of Internet

Internet maps its derivation back to 1969 when it evolved out of an experiment carried by the defence agency of United States. The Department of US Defence was in a process of doing research and technical development in the areas where few services of defence (Army, Navy, Air force, Marine corps) had clear jurisdiction of operations.

This agency i.e, ARPA (Advanced Research Project Agency), which was later known as DARPA (Defence Advanced Research Project Agency), planned to create a computer network that would continue to operate even during the emergency or disastrous situations like war.

This led to the development of ARPANET (Advanced Research Projects Agency Network) which worked to link US Scientific and Academic Researchers for exchanging data and messages between one computer to another. ARPANET started as a four node network in December 1969.

By 1970’s, ARPA helped in the development of a new protocol known as TCP/IP (Transmission Control Protocol / Internet Protocol) for transferring and tracking of data between the networks so that they can reach the destination safely.

By 1980’s, another federal agency of US named National Science Foundation (NSF) used ARPANET to connect its five regional supercomputer centres located at different universities so that their multiple users could share the resources among themselves. Later, NSF created a more sophisticated network called NSFNET (National Science Foundation Network) which was a series of network that was utilized for research and development.

The link between ARPANET, NSFNET and other networks was termed as Internet. (The process of connecting separate networks with each other is called Internet working. A collection of ‘networked networks’ is described as being inter-networked i.e., from where the ‘Internet’ gets its name).

Initially NSFNET was meant only for the purpose of academic research and was not in use for any private organization. As NSFNET did not permit its use to private organization, several private telecommunication companies built their own network backbones that used the same set of networking protocols as NSFNET.

The original ARPANET lost its existence in 1990 and the government discontinued funding NSFNET in 1995 and the commercial internet services replaced them. By early 1990’s, internet expanded dramatically and the tool which was made for communication in wars found its way into general and commercial use (i.e., business, home, education, etc.).

Internet Terminology

Let us now learn about some basic terms related to Internet we come across in our daily lives.

Web Servers

A web server is the principal computer or server that stores the contents of different websites. It provides data and information to computers on request which are connected to it through the network via Internet.

In other words, it can be said that it is a computer that stores data and runs software that is designed to send web pages in file format when requested by web browsers.

The server is usually a computer of high configuration i.e., with large storage capacity and high speed processor that stores data and executes the instructions very fast.

Web server is responsible for accepting requests from the client i.e., web browser and responding in the form of web pages. It accepts connections from web browsers and whenever an HTML document is requested, it is sent using HTTP protocol. The server computer should have a high-speed connection to the Internet and should be powerful enough to handle multiple simultaneous connections at the same time.

Some popular web servers are Apache, IBM Lotus, ‘Internet Information Server (IIS)’ of Microsoft, etc. Apache is an open source web server.

A web client is the host computer that requests different types of services from the web server. The clients may be PCs, Software or workstations.

Web Clients

‘Client’ and ‘Server’ are two parts of an online connection. A client is any computer that requests information from the server and a web server is a computer that stores the data and the source application.

A web client is actually the browser on client’s computer that makes the requests to the remote server. A computer that uses a web (client) browser is referred to as a web client.

Web Site

A location on the web server where an individual or a company or any organization uploads its information is known as a website. It is a collection of one or more web pages that display information with the help of a web browser. A website can be compared to a book that contains different chapters in the form of web pages.

The first page of a website is called ‘Home Page’. The pages on a website are linked to one another and a person can navigate to any page by clicking on the links called ‘Hyperlinks’.

Websites are hosted on the web server on a rental basis by the ‘Internet Service Providers’. In order to access them, every website is provided with a unique name. The websites may be owned by individuals, agencies, companies, colleges, universities, government bodies, etc.

Web Page

A web page is a document of information that can be accessed and viewed through a web browser. A web page is generally contained in a website and constitutes as a source of information that floats on the world wide web. The information is usually coded in HTML. Web pages may be retrieved from a local host computer or from a remote computer with the help of the Internet. Web pages are requested and served from a web server using protocols like Hyper Text Transfer Protocol (HTTP).

Web pages may consist of static pages (which are stored within a file system of a web server) and/or dynamic pages (which contain files of run-time nature i.e., which facilitates online data transformation). Web pages may contain information in the form of text, images, pictures, sound, audio, video, etc.

HTML is used to publish web pages. A web page is designed by web developers with the help of markup languages like HTML. It is not technically a programming language but it was developed to create electronic pages that could be displayed on the Internet.

Web Browser

A web browser is an application software that helps a user to navigate through different websites on the Internet and display web pages. The user requests a page from a web server with the help of web browser. After receiving the request through the web browser, the web server makes it available for a web browser to display the page.

Web browsers can also display animated images, play sound and video, provide secure connections and much more. Some common web browsers are ‘Internet Explorer’, ‘Mozilla Firefox’, ‘Opera’, ‘Apple Safari’, ‘Google Chrome’, ‘Microsoft Edge’, ‘Lynx’ (Text only mode web browser), etc.

Web Address

Web Address is the name for identifying a website on the Internet. On Internet, there are numerous web sites; it is only with the help of web address that we can find a particular website.

Text based addressing system on Internet is called Domain Name System (DNS). In this system, each website has a unique name such as www.orangeeducation.in, www.google.com, etc.

The last two or three letters of the web address is called Top Level Domain (TLD) that provides information about the root of the domain for the type of organization to which the address belongs to. It is alphabetical and helps to identify an address in Domain Name System.

Some common Top Level Domains are:

In DNS, codes of countries can also be included. The code comprises of two letters. Some common codes of certain countries are:

Blogs

What if, you could maintain your personal diary on the web? Yes! You can make your own diary on WWW and publish your own articles or ideas on the Internet by blogging. Blog refers to the personal content on the net which is uploaded by a user. It refers to the online publication or uploading of personal or general information for restricted viewing. It contains the personal content on website that is maintained by individuals with regular entries of personal comments, descriptions of events, personal news or other material which can be in the form of text, audio, video, graphics, etc.

Blogs have evolved since logging of personal information on the web during 1997 by Jorn Barger. Initially, blogs were text documents that were manually updated as components of websites. It had limitations as large number of uploaded publications could not be browsed easily. But with the passage of time and development of new tools on the web, the publications could be managed in a more organized way, as the articles could be browsed in reverse chronological order which led to broader usage of blogs. There are many blogging sites, for example ‘www.blogger.com’, ‘www.bloglines.com’, etc. Blogs can be categorized into different types like :

Personal Blogs

Personal blogs are the most common and traditional blogs. Personal blogs can be sentimental which can sometimes be read by the blogger only. It also allows bloggers to share their thoughts and feelings instantaneously with friends or others. An example of a personal blog is Twitter (www.twitter.com).

Corporate Blogs

Blogs can be uploaded for business or commercial purposes. Such blogs can be used internally to enhance the communication among different employees of an organization or for taking feedback from customers or for providing information in general for marketing, promotion of brand or public relations.

A corporate blog is published and used by an organization to reach its organizational goals. Corporate blogs can be broadly classified into: Internal blogs, External blogs and CEO blogs.

Genre Blogs

Genre blogs are meant for the publication of articles on specific topics or a particular subject, such as Political blogs, Travel blogs, House blogs, Fashion blogs, Educational blogs, etc.

Spam Blogs

Spam blogs are used for the sole purpose of spamming. Spam blogs are usually a type of scrapper site in which the contents are either unauthentic text or merely stolen or copied from other websites.

Such blogs usually contain a large number of links to sites associated with the blog which are often disreputable or useless websites.

Newsgroup

A newsgroup refers to a forum on the Internet where people share ideas about topics of mutual interest. The topics of interest may be from areas like politics, technology, sports, etc. Newsgroups, which are also referred to as ‘Usenet’, are international discussion groups that focus on