Internet

BY-

AMAN SINGHAL

SECTION-E

ROLL NO.-58

BRANCH-MECHANICAL ENGINEERING

What Is the Internet ?

A network of networks, joining many government, university and private computers together

The vast collection of computer networks which form and act as a single huge network

What is the Internet ? (contd.)

•The largest network of networks in the world.

•Uses TCP/IP protocols and packet switching .

•Runs on any communications substrate.

Technology

• The architectural design of the internet software has been delegated to the Internet Engineering Task Force (IETF). 

•IETF makes standards about the internet architecture

TCP/IP The framework

standardized by IETF is also known as TCP/IP. Framework is as follows-

At the top is the Application Layer.

Below this top layer is the Transport Layer

Below Transport Layer is the Internet Layer which consists of two layers.

At the bottom is the Network Access Layer which is the software layer.

Other frameworks-

Other models have been developed, such as the Open Systems Interconnection (OSI) model, but they are not compatible in the details of description, nor implementation.

Evolution of the Internet•Internet was the result of several research works that were done to connect many physically seperated networks.

•It expanded and popularized in 1990.

Networks that led to Internet

•ARPANET (Advanced Research Projects Agency Network).

•X.25 and public access.

•UUCP (Unix-To-Unix Copy Protocol ).

•NPL (National Physical Laboratory ).

Functionality of the Internet

•Internet needs a proper addressing system for communication.

•This system of addressing is called the Internet Protocol Addressing System.

Domain Naming System (DNS)

• It is the hierarchical naming system for computers and its services.

•It serves as a phonebook for internet by translating human-friendly computer hostnames into IP address.

Let us consider an address-

www.geu.ac.in

Here,

www is the host name.

geu.ac.in is the domain name.

ac.in is used for educational institutions present in India.

An address and its parts.

Uses of the Internet.

•E-mail.

•World Wide Web.

•Web Search Engines.

•Data Sharing (FTP).

Other Uses-

•Social Networking.

•Usenet.

E-MAIL

•E-mail is a method of exchanging digital messages.

•The e-mail that we use today was created in ARPANET in 1973.

•E-mail format is defined in RFC 5322 and also in a series of RFCs from RFC 2045 to RFC 2049.

Different kinds of mail system

•Host-based mail system.

•LAN-based mail system.

•ARPANET-based mail systems.

Uses of the E-Mail

•In society.

•Flaming.

•E-mail bankruptcy.

•In business.

The World Wide Web

•It is a system of the interlinked hypertext documents contained on the Internet.

•Internet and World Wide Web are the two different terms having different meanings.

•WWW prefix is an Internet host.

Web Search Engines.

•It is a tool designed to search for information on the World Wide Web.

•Before search engines there was a complete list of all web servers.

•The first tool for searching on the internet was Archie.

•The first search engine was Aliweb which came in 1993.

Functioning of a Web Search Engine.

A web search engine operates in

the following order-

1. Web Crawling.

2. Indexing.

3. Searching.

File Transfer Protocol.

• It is a network protocol used to exchange and manipulate files over a TCP/IP based network.

• It follows two primary transfer modes-

1. ASCII mode.

2. Binary mode.

Advantages and Disadvantages.

Thus at last we discuss few advantages and few disadvantages of Internet-

Advantages-

•Communication.

•Information.

•Entertainment.

•Services.

•E-commerce.

Disadvantages-

•Theft of personal information.

•Spamming.

•Virus threat.

•Pornography.