The Internet & The Web : Features - Internet & World Wide Web, E-Commerce | E-Commerce - B Com PDF Download

OBJECTIVE
Most early internet programmes were command-line programmes. The World Wide Web has changed all that. Instead of requiring to know archive commands, the www gives a graphical view of the internet. The web is easy to use; it is easy to create web pages and to link them to other web pages.
After going through this lesson, you will be:

• Describe the advanced internet concepts
• Explore various internet tools and www technologies

INTRODUCTION
Internet is a network for the elite, but it is very egalitarian. It has valuable information but works at no extra charge.
The Internet is a rapidly growing network of thousands of business, educational and research networks connecting millions of computers and their users in over 100 countries. Internet is very popular in the recent days, though it took birth in the late 1960’s. The US Government started the process when they laid the framework for the Internet. The Department of Defence (DOD) decided to fund a network of computers that would all talk the same language. The intention was to connect researchers, government workers and defence contractors who were providing systems and data to government agencies. Most brands of computers at that time applied different rules for communication (protocols). DOD decided to develop a vendor-independent suite of protocols. The new network was named ARPANET (after the Advanced Research Projects Agency) within DOD that provided the funding.
ARPANET protocol was replaced in 1970’s by TCP/IP protocol suite. The features in these protocols permitted transmission of data in an efficient way from any computer connected to the ARPANET to any other on the net. It is thus the foundation for the Internet as we know today. The chronological events that took place are as under:
1969 First ARPANET installed at UCLA in Sept. 1969 : ARPANET used special purpose computers IMPs (Interface Message Processors); created Network Communication Protocol (NCP)
1972 E-mail was invented by accident for sending messages by two programmers. Ray Tomlinson of BBN is credited for sending the world’s first e-mail message in 1973; First Killer application for commercial users.
1973-74 In mid 1970s, Transport Control Protocol/Internet Protocol (TCP/IP) was developed by vintcerf to link different packet networks; These were capable of connecting multiple independent networks through routers/gateways.
1978 US government preferred TCP/IP;
1980 DARPA funded the development of Berkley UNIX TCP/IP was made part of the operating system.
1980-86 National Science Foundation (NSF) supported the development of CSNET, a computer I science research network. CSNET became popular (with 170 universities, other organisations: and networks in other countries).
1986 NSF initiated a new program of networking and computer support for super computing centers for research. IT launched the NSFNET network backbone program.
1987 CSNET merged with BITNET, the backbone was upgraded from 56 Kbps to TI service (1.5:1 .Mbps); TI was operational in
1988-1991 CSNET service discontinued. Internet connectivity had become essential tool for the conduct of scientific research; NSFNET program had outgrown its initial vision (of 1985). Successor program established by High performance computing act of 1991.
The three parallel activities of this are :
-Commercialization of the Internet (as found even today)
-High performance computing and communications (HPCC Program) (As found even today)
-National Information infrastructure (Information Superhighway) (As found even today).
US government requirement was to ensure that the system way secure and would allow continued cooperation between these sites and computers in the case of nuclear attack.

The internet evolved from a military focus towards non-military use with many simultaneous developments like:

•  E-mail
• Office productivity applications
• personal computer
• Software products workgroup computing
• Local area network

ADVANCED CONCEPT OF INTERNET 

Uniform Resource Locator

A URL (or uniform resource locator) is the address of an Internet page on a Web site. Usually it consists of four parts: protocol, server (or domain), path, and filename. Often, when you go to the very first page of a Web site, called the home page, there’s no path or filename. Here’s an example:

Communication Protocol Protocol is a set of rules created for the process of communication with another computer or with an operating system

The first element in the URL is the protocol. This is the service that provides the resource, followed by a colon. The default taken is if you don’t specify other service. The protocol specifies the computer language used to transfer information. Specifically, a protocol tells the browser where the information is located (for example, on a web server, an FTP (file transfer protocol) server, a local hard drive, and so on). The protocol tells the browser what to expect from the document retrieval process.

Host Name: host name is the server that contains the resource, preceded by two slashes (either. in the form of a domain name or an IP address). In other words the hostname is the name of the server that holds HTML documents and related files.

Folder name: folder names give document on the servers file system. Folders perform the same function on a web server that they perform on your PC (i.e. they organize documents). There’s virtually no limit to how deep you can nest folders, and there’s no limit as to what files the folders can contain.

File name: file names are the names of specific documents. It identifies the file (an HTML document, an image, a text file, and so on) to be displayed. In the above example, the file index.html is displayed. This file is kept in the folder virtual.

Transmission Control Protocol / Internet Protocol (TCP/IP) : Transmission Control Protocol and Internet Protocol ( TCP/IP ) are most commonly used protocol in the Internet. They mainly deal with slicing the data into small sized packets and routing them along the communication channel. These packets are routed to their destination and passed through from node to node and are assembled in order to form the data at the destination computer.

TCP/IP is a very popular protocol used in conjunction with internet. To establish a link between two computers on the internet, it is required to frame certain rules and regulations so that the data communication between the computers may take place. A protocol means a set of rules which is accepted globally. TCP/IP is the protocol which defines the rules and algorithm for data communication between different computers.

To establish a link between two or more computers, it is required to define the address of the computer. This address must be unique. Rules and regulations for secure transmission of data over the communication channel are also required. TCP/IP is divided into two set of protocols one is called TCP or Transmission Control Protocol and other is called IP or Internet Protocol.

Transmission Control Protocol : This deals with packets over networks. The packets are small pieces of data meant for effective and safe communication over the network. To send a block of data over a communication channel, the data is divided into various pieces and these pieces of data are communicated as packets. These packets’ have to follow a long path, traversing from one computer or node to another computer. This process is called routing. The size of packets is decided on the basis of network capability. The TCP also ensures the safe delivery at the destination and the assembling of all the packets to get the complete lot of data at the destination computers.

Internet Protocol : This mainly deals with the addresses of computers. The Internet Protocol decides the address of computer to be labelled on the packet. This allows various computers or intermediate nodes to read the address of the destination computer and route the packet to the destination node.

Hyper Text Transfer Protocol (HTTP) : A web page is transferred to a user’s computer via the hypertext transfer protocol (HTTP). HTTP is the method through which hypertext files such as web pages, are transferred over the internet. HTTP is a client/server based internet protocol.

Web pages generally reside on HTTP servers. A user requests a web page from an HTTP server through his or her web browser client software. Either by clicking on a hypertext link or designating a particular URL (uniform resource locator). The server then sends the requested information to the user’s computer. The browser software interprets the HTML codes and presents the information contained in the web page in a readable format on the user’s computer.

File Transfer Protocol (FTP) : FTP is part of the TCP /IP protocol suite. It is a protocol or set of rules, which enables files to be transferred between computers. Ftp works on the client/ server principle. A client programme enables the user to interact with a server in order to access information and services on the server computer. Files that can be transferred are stored on computers called FTP servers. To access these files, an FTP client programme is used. This is an interface that allows the user to locate the file(s) to be transferred and initiate the transfer
process.

Anonymous ftp allows a user to access a wealth of publicly available information. No special account or password is needed. There are a wide variety of files that are publicly available through anonymous ftp. They are:

Shareware: software that you can use free for a trial period but then pay a fee for the licensed version.

Freeware: completely free software, for example fonts, clipart and games.
Upgrades and Patches: upgrades to amend software and fixes for software- problems available either free or against charges.

Documents: examples include research papers, articles and Internet documentation.

Files on FTP servers are often compressed. Compression decreases file size and this enables more files to be stored on the server and makes file transfer times shorter. In order to use a compressed file the user needs to decompress it using appropriate software. It is a good idea to have current virus checking software on the computer before files are transferred on it.

Ws-FTP32 LE is a top rated and very popular FTP programme from John Junod. It is given away free to certain non-commercial users.

Simple Mail Transfer Protocol (SMTP) : This protocol is used for the delivery of E Mail. When an E mail is to be sent, then the Mail Transfer Program contacts the remote machine and forms a TCP connection over which to e-mail is transferred. Once the connection is established, then Simple Mail Transfer Protocol (SMTP) identifies the sender itself, specifies the recipient of mail and then transfers the E mail message. Other features included in the SMTP are that it allows the sender to ask whether the mailbox to which the mail is directed, does exist on the remote computer or not. It also enables the sender to keep a copy of the mail until it removed or deleted.

Post Office Protocol : If you’re accessing the Internet using a PC or Macintosh, there are several different ways you can read and send email. One of the more popular applications uses the Post Office Protocol (POP). In a nutshell, the POP system allows your personal workstation to get its email from a big computer that serves as a post office, delivering the mail when you (or your computer) ask for it. This eliminates the need for your computer to be on all the time, constantly available to receive email. In order to use a POP-based email application, you need Internet access (via dial-up or full-time connectivity) and a POP mail account on a post office computer (ask your Internet provider). All of these applications provide intuitive editors.

Point to Point Protocol (PPP) : This is used when the Internet is accessed using a telephone line. Normally, in India, the server of the Internet Service provider (ISP) is accessed from the home or office through the telephone line. PPP is the set of rules which specify how the data will be communicated over telephone line from your computer when the connection with your ISP has been established. This protocol is used in conjunction with Serial Line Internet Protocol (SLIP).

This protocol is used when the communication is done over a serial transmission line like the telephone line. The protocol allows the user to use GUI based web browsers like Netscape and MS Internet Explorer. Internet Service providers use the PPP and SLIP account to enable users to view graphics on the Internet. These accounts assign an IP address to your computer when a connection is established.

 Telnet

Telnet is a protocol, or set of rules, that enables one computer to connect to another computer. This process is also referred to as remote login. The user’s computer, which initiates the connect icon, is referred to as the local computer and the machine being connected to, which accepts the connection, is referred to as the remote or host computer.

Once connected, the user computer emulates the remote computer. When the user types in commands, they are executed on the remote computer. The user monitor displays what is taking place on the remote computer during the telnet session.

Gopher

Gopher is a protocol designed to search, retrieve and display documents from remote sites on the Internet. It accomplishes this using the client / server model of users running client software on their local machines that provide an interface that interacts with remote servers or computers that have information of their interest. In addition to document display and document retrieval, it is possible to initiate on-line connections with other systems via gopher. Information accessible via gopher is stored on many computers all over the Internet. These computers are called gopher servers.

Users interact with gopher via a hierarchy of menus and can use full-text searching capabilities of gopher to identify desired documents. Once an appropriate item is selected, gopher retrieves it from wherever on the network it resides and (if it is text) displays it. The users may feel as if all the information available to gopher resides on their local computer, when in fact, gopher is interacting with a large number  of independently owned and operated computers around the world. Gopher client software exists for most computer platforms.

Archie

These are thousands of anonymous ftp servers around the world offering more files than you can imagine. The role of Archie is to make the whole system manageable by helping you find what you need. There are a number of Archie servers around the net, each of which consists a database of most of the files that are publicly available via anonymous
ftp.

Suppose you want a particular file -for instance, a programme but you don’t know which anonymous ftp server has the file. You use an Archie client to convert to an Archie server. You can have your client ask the server to search for files that have the same name as the programme you want.

After a short wait, the server will send back a list of addresses of some of the Internet sites that have files with that name. Once you know where to look, it is a simple matter to use ftp to download the file. The term Archie was chosen to express the idea of an
archive server.

Veronica and Jughead : Like the web, Gopherspace is large and full of menu items than you could ever find on your own. To help you find things in Gopherspace you can use veronica: a tool that keeps track of an enormous number of gopher menu items from all over the net. You can use Veronica to perform a search and look for all the menu items in gopherspace continuing certain keywords. A related tool, Jughead does the same thing for a specific group of gopher menus, say, and all the menus at a particular university.

After Veronica or Jughead finishes searching, you will be presented with a new menu containing the names of whatever items were found. To access one of these items, all you need to do select it, and your gopher client will connect you to the appropriate gopher server automatically. The results of a typical Veronica search will be items from around the net, but you won’t need to know any of the details: your client will take care of everything for you.

Wide Area Information Service (WAIS) : WAIS is an Internet search tool that is based on a certain protocol. It works on the client / server principle. A WAIS client programme enables the user computer to contact a WAIS server, submit a search query and receive a response to that query.

WAIS has the capability of simultaneously searching more than one database. After the search phrase has been typed into the client interface, the user can then choose which databases should be used to complete the search. Depending on the WAIS client software being used, this may be a matter of using a mouse to select database names displayed on a screen, or of typing in the database names using the keyboard. It is very important to know that WAIS indirectly searches the database. The database itself is not being searched for the requested search phase. Rather, an index for the database is searched. The index is created by people, and can contain all, or a number of words in all of the items contained in the database. Once the search has been executed, all items containing the words appearing in the search phrase will be returned to the user, provided that the words in the search phrase appear in the indexes of the selected databases.