Internet basics

History of Internet

• 1960 – ARPANET (Advanced Research Projects Agency Network) 

• 1970’s – TCP/IP Transmission Control Protocol and Internet Protocol 

• 1990 – World Wide Web (WWW)

The complete history and origin of Internet

Internet Timeline

Internet V/s World Wide Web

• A network, in computing, is a group of devices that can communicate each other and share resources. 

• Internet is a network of networks. It is a global network of billions of computers and many other electronic devices. 

How the Internet Works?

IP Address

• Every computer connected to a network has its own unique number, called an IP address. 

• IPv4 address is 32 bits (4 bytes) long and consists of two components: network component and host component. 

• Each of the 4 bytes is represented by a number from 0 to 255, separated with dots.

• For example in 216.52.1.250. 

• IPv6 creates more complex newer alphanumeric IP addresses such as 2400:cb00:2048:1::c629:d7a2.

TCP/IP

TCP/IP, or the Transmission Control Protocol/Internet Protocol, is a suite of communication protocols used to interconnect network devices on the internet. TCP/IP can also be used as a communications protocol in a private computer network like an Intranet

Request and Response

In a typical WWW example, you type in a URL in your browser’s location window, and press enter.

Your browser then sends a message (request) to a web server, requesting for a given HTML page.

The web server sends  back the page, or a response if the page cannot be found

Domain Name System

• The Domain Name System (DNS) assigns recognizable and easy to remember host names instead of IP address

• www.wikipedia.org - IP address 103.102.166.224

• The first-level set of domain names are the top-level domains (TLDs)

• Generic Domain - .com, .biz, .gov, .org

• Country Level Domain - .in, .uk, .us

• Below this are the second-level and third-level domain names. They appear directly left to TLDs

• The registration of the domain names is usually administered by domain name registrars

• Internet Corporation for Assigned Names and Numbers (ICANN) authorises domain name registrars

.IN Domains

• .IN is India's top-level domain on the Internet. Like .COM, .IN can be used for e-mail, Web sites, and other applications. But unlike other domains, .IN is a unique symbol of India and its role in the world.

• .IN domains are easy to buy, easy to use, fast and reliable! Anyone can register an .IN domain

• INRegistry is the official .IN registry. It was appointed by the government of India, and is operated under the authority of NIXI, the National Internet eXchange of India.

.NIC.IN, .EDU.IN & .GOV.IN

• The Domain name 'NIC.IN' is owned by National Informatics Centre (NIC) and the same can be allocated ONLY to Indian Government Entities

• NIC is the authorised registrar for 'GOV.IN' Domains and it is advised to all Government Departments (Central & State) to host their websites under 'GOV.IN' Domain names

• ERNET  (Education and Research Network) is the exclusive registrar for the AC.IN, EDU.IN & RES.IN Domain names.

Web Browsers

• A web browser is a software application for accessing information on the World Wide Web.

• The first web browser, called WorldWideWeb, was created in 1990 by Sir Tim Berners-Lee

• Mosaic (1993) is credited as "the world's first popular browser“

• Popular browsers

• Google Chrome

• Apple Safari

• Opera

• Internet Explorer

• Mozilla Firefox

Websites

• A website is a collection of web pages and related content that is identified by a common domain name and published on at least one web server. (Wikipedia)

• It will have a homepage and many related pages/files

• Homepage refers to the main page that provides access to all the other pages or information on the site

• A Web Page is the basic unit of every website

• It may contain text and multimedia

Hyperlink

• A hyperlink or link is a word, phrase or image clicking on which you can get access to a resource on the Internet.

Learn more about Hyperlinks

Uniform Resource Locator (URL)

• Uniform Resource Locator uniquely identifies a document over the internet.

• Domain name is component of URL

• We access a resource through the URL

HTML (Hypertext Markup Language)

Hypertext Markup Language is the standard markup language for documents designed to be displayed in a web browser. Developed by Tim Berners-Lee in 1990, HTML provides for the structure of a web page.

You can learn HTML through this tutorial

Internet Service Providers (ISPs)

An Internet service provider is an organisation that provides services for accessing, using, or participating in the Internet. As we know, Internet is a network of networks. We get connected to the Internet through the ISPs. 

• ISP is a company like BSNL that offers its customer access to the Internet. 

• ISP’s allot your computer an IP Address and provides access DNS server.

• ISPs in India:

• BSNL, MTNL

• Airtel

• Reliance Jio

• Idea

• Vodafone etc.

Who Controls the Internet?

• The Internet is a public, cooperative, and independent network. The following bodies controls some aspects of the Internet.

• Internet Corporation for Assigned Names and Numbers (ICANN): Its task is to manage the logistics of Internet Protocol (IP) addresses and domain names.

• World Wide Web Consortium (W3C): Its task is to develop and tests advanced Internet technologies.