Evolution of Internet

The internet traces its origin back to the 1960s when it grew out of an experiment conducted by the US Department of Defence. They wanted to create a computer network that could continue to function in the event of a disaster such as a nuclear war. The network was known as ARPANET (Advanced Research Projects Agency Network). It was the forerunner of today’s internet.

Evolution of Internet
Evolution of Internet

The internet traces its origin back to the 1960s when it grew out of an experiment conducted by the US Department of Defence. They wanted to create a computer network that could continue to function in the event of a disaster such as a nuclear war. The network was known as ARPANET (Advanced Research Projects Agency Network). It was the forerunner of today’s internet.

By the 1970s, ARPA (Advanced Research Projects Agency) helped in the development of a new protocol known as TCP/IP (Transmission Control Protocol/Internet Protocol) for transferring data between the networks. The TCP/IP is the core of the internet.

In the 1980s, Usenet newsgroups and Electronic Mail (e-mail) came into use. Indices such as Archie and the Wide Area Information Server (WAIS) were also created to keep track of the information on the internet. The University of Minnesota created gopher, a simple menu-driven system for accessing files.

The Internet really became popular in the 1990s after the development of the World Wide Web (WWW).

In 1991, CERN (Conseil European pour la Recherche Nucleaire) released World Wide Web, also known as the “web”. The CREN team developed the protocol based on hypertext (HTTP) that makes it possible to connect content on the web with hyperlinks. The WWW permitted access to information using a Graphical User Interface (GUI) information across the network without being a computer expert and without knowing the exact physical location. Now the websites are able to provide users with knowing the exact physical location. Now the websites are able to provide users with a wide range of experiences such as pictures, multimedia (sound, video), and interactivity.

With the growth of the internet, the quality, quantity, and variety of information also grew. The internet is a repository of every consumable type of information.

BASIC INTERNET TERMS

Web page:

The World Wide Web consists of files called pages or web pages that contain information and links to resources throughout the internet. A web page is an electronic document written in a computer language called HTML (HyperText Markup Language). On the web, the user can navigate through the different web pages of information in accordance to the interest of the user.

Website:

A website is a set of related web pages, published by an organization or individual. A website contains a home page along with other additional web pages. Each website is owned and updated by an individual, company, or organization. It is an area on the web, which is accessed by its own address.

Home page:

A home page is a starting point for the website. The home page usually provides an overview of what could be found on the website. If there is not much information, the home page may be the only page of the website.

Browser:

A browser is a computer program that accesses web pages and displays them on the computer screen. It is the basic software that is needed to find, retrieve and send information over the internet. The most popular browsers are Microsoft Internet Explorer and Netscape Navigator.

Browsers are of two types:

1. Graphical browsers:

These allow retrieval of text, images, audio, and video. Navigation is accomplished by pointing and clicking with a mouse on highlighted words and graphics. Both Internet Explorer and Netscape Navigator are Graphical browsers.

2. Text browsers:

These provide access to the web in text-only mode. Navigation is accomplished by highlighting emphasized words on the screens with arrow up and down keys and then pressing the Enter key to follow the link. Lynx is an example of a text-based browser.

Uniform Resource Locator (URL):

Each web page has a unique address called Uniform Resource Locator (URL) that identifies its location on the internet. Web browsers utilize the URL to retrieve a file from the computer on which it resides. The format of an URL consists of four parts: protocol, server (or domain), path, and file name.

Eg: http://www.xyz.com/tutor/start/main.htm

The structure of this URL is

Protocol: HTTP

host computer name: www

Domain name: xyz

Domain type: com

Path: tutor/start

Filename: main.htm

Hypertext:

Hypertext refers to the text that connects to other documents. These texts are known as hypertext links, hyperlinks, hotlinks, or simple links. A hyperlink is used to move to another part of the same page or to load a different webpage. Hypertext is a method of instant cross-referencing. It is used for organizing information and linking related documents together using words and graphics.

Usually, hypertext links appear in a different color. When the cursor moved over a text link or over a graphic link, it will change from an arrow to a hand.

Internet Service Provider (ISP):

An Internet Service Provider (ISP) is an organization that provides the required software which is used to connect to the internet.

Web Server:

A server is a computer equipped with server software that provides a specific kind of service to client software running on other computers. The term can refer to a particular piece of software, for example, a web server or to the machine on which the software is running.

A web server is a computer that answers requests from the user’s computers. Web servers can run on any hardware platform and operating system and store documents in HTML.

Download and upload:

The download refers to the activity of moving or copying a document, program, or other data from the internet. It is a process of “pulling” information from one computer onto another. For example, while accessing a website, the HTML code and graphics must be downloaded from the remote server onto the user’s computer before viewing the website.

Upload is just the opposite of download. In case of uploading, the user moves or copies a document, program, or other data from the computer to the internet. Upload refers to the act of moving data from one computer to another, usually from a server to a remote computer. For example, a software company may upload a demonstration of its new software onto the web so that users can then download the software onto their individual computers.

Online and Offline:

The term online is commonly referred to as connected to the world wide web via the internet. Offline is just the opposite of online and it refers to the actions performed when the user is not connected via telecommunications, to another computer, or a network like an internet.

Getting connected to the internet

The basic requirements of getting online are,

The TCP/IP enabled computer with a web browser

An account with an ISP

A telephone line plugged top of a suitable socket

A modem to connect the computer to the telephone line

The internet is a bunch of computers linked together through a network so computer users in different locations can have access to the same information.

The computer:

The computer may have at least 386 microprocessors chip with a minimum of 16MB of RAM. For a good browsing experience, use a faster chip with more RAM. In addition, a color monitor with at least 640*480 resolution and a capability of displaying a minimum of 256 colors. The system should possess a hard disk with 200 MB of free space to store internet software and temporary internet files.

Modem:

A modem (Modulator-demodulator) is hardware that converts digital data into analog signals that can be sent over an analog telephone line and convert the analog signal back into digital data. Thus, when the modem receives data from a web server via the phone system, it reconstitutes the analog signal into digital form so that the computer can understand it. Modem speeds are measured in kilobits per second (kbps). The modern modem supports 28k to 56k speeds.

Modems are of two types:

1. Internal modem:

It is a card that is fitted inside a computer with a lead running directly from the computer to the phone socket.

2. External modem:

It is a small external box wired between the computer and the phone socket.

TYPES OF INTERNET CONNECTION

The modem must be connected to a telephone line to access the web. Modems do not need a special telephone line. Most people use their regular phone line to connect to the internet. some of the other common types of internet access are briefed below.

1. Dial up:

A dial-up connection is the access method that uses telephone lines to connect to the internet. It is the most common way that individuals who can use home computers connect to the internet.

2. ISDN:

It stands for Integrated Service Digital Network and is more common business and commercial use. ISDN involves the digitization of telephone networks so that voice, graphics, text, and other data can be provided to users from a single terminal over existing telephone writing.

3. cable modem:

A cable modem connects the user to the internet through a cable television line. A cable modem will have two connections, one to the television outlet and the other to the computer. Cable modems not only provide faster internet access but also give added interactivity to the television.

4. Leased line:

The facility provides reliable, high-speed internet access ranging from 2.4 kbps to 45 Mbps. A leased lines connection is a way to link two or more sites for a fixed monthly charge. A leased line facility can be provided via fiber optic or copper lines.

5. DSL:

DSL or Digital Subscriber Line service is provided through the existing phone line but it works differently than regular analog modem dial-up access. DSL operates over normal telephone lines and it can be used simultaneously with the telephone. DSL can increase the connection speed.

6. Broadband:

This type of access is good for remote locations. Satellite connection can be either a two-way service or a one-way service. In the case of a two-way satellite service, the data is transmitted via satellite to a dish antenna at the user’s house. In a one-way system, the user needs a conventional modem and telephone link to ISP.