Introduction of Internet :
The internet is “a network of networks”. It is a global collection of high powered computers that are connected to each other with network cables, telephone lines, microwave dishes, satellites etc. Some computers (servers) on the internet store documents, sound files, video clips, program files, electronic shopping centers, animations, pictures, interactive contents and other information that can be stored and presented electronically. All these resources are available to all computers connected to the internet.
The internet is a globally connected network of computers that enables people to share information and communicate with each other. It is the largest WAN that connects billions of computers, smart phones and millions of LANs from different continents.
It is the global network of computing devices including desktop, laptop, servers, tablets, mobile phones, other handheld devices, printers, scanners, routers, switches, gateways, etc. Moreover, smart electronic appliances like TV, AC, refrigerator etc can also communicate through a network.
The internet can be known as a kind of global meeting place where people from all parts of the world can come together. We can communicate with anyone on the internet by sending e-mail, posting messages in newsgroups, chatting in various chat areas and even telephoning and video-conferencing over the net.
The internet is evolving every day and it is difficult to visualize or describe each and every aspect of the architecture of the internet. Computers are either connected to a modem through a cable or wirelessly (Wi-Fi). That modem, be it wired or wireless, is connected to a local Internet Service Provider (ISP) who then connects to a national network. Many such ISPs connect together forming a regional network and regional networks connect together forming a national network, and such country-wise networks form the Internet backbone.
The internet today is a widespread network, and its influence is no longer limited to the technical fields of computer communications. It is being used by everyone in the society as is evident from the increasing use of online tools for education, creativity, entertainment, socialization and e-commerce.
History of Internet:
Internet started with the ARPAnet and a few resourceful computer scientists who wanted to share files among people working on similar projects. ARPA is the acronym for Advanced Research Projects Agency of the United states Department of Defense. In September 1969, the University Of California at Los Angeles (UCLA), The Stanford Research Institute (SRI), the University of California, Santa Barbara (USCB) and the University of Utah were connected. And this network is called ARPAnet. Although the original aim of this research was military, it was soon used for other purposes. Other universities and research and commercial organizations soon began to use this technology to create their own networks, some of these networks then connected to the ARPAnet.
January 1, 1983is considered the official birthday of the internet. Prior to this, the various computer networks did not have a standard way to communicate with each other. A new communication protocol was established called transmission Control Protocol/ Internet Protocol (TCP/IP). This allows different kinds of computers on different networks to “talk” to each other. ARPAnet and the Defense Data Network officially changed to the TCP/IP standard on January 1, 1983, hence the birth of the internet.All networks could now be connected by a universal language.
Internet Protocols:
Protocols are sets of rules for message formats and procedures that allow machines and application programs to exchange information. These rules must be followed by each machine involved in the communication in order for the receiving host to be able to understand the message.
The main protocol for transferring information on the web is the Hypertext Transfer Protocol (HTTP). Web pages, both text and graphics are sent from the server to the browser using this protocol.
The web also supports most of the other popular internet protocols, such as TCP/IP, FTP, PPP, SLIP etc. But we need not remember all these protocols. The browser does all the work, dynamically switching between protocols as needed.
Intranet:
Intranet is a local or restricted network that enables people to store, organize and share information within an organization. It is a private computer network built inside an organization or a company. Usually each company or organization has their own intranet network and employees of that company can access the computers in their intranet. Computers in intranet are not available to the world outside of the intranet. Each computer in intranet is also identified by an IP address, which is unique among the computers in that intranet. Any of the well known internet protocols may be found in an intranet, such as HTTP, SMTP, and FTP. Intranet sites are accessible via web browser in similar way as web sites in internet, but only members of internet network can access intranet hosted sites.
Intranet systems require a great deal of security, in order to protect the system from unauthorized access. This means IT professionals who set up and maintain intranet systems must install effective firewalls, anti-malware and anti-spyware programs.
Internet Vs Intranet:
The internet is open, public space, while an intranet is designed to be a private space. An intranet may be accessible from the internet, but it is protected by a password and accessible only to authorized users.
|
|
Internet |
Intranet |
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1. |
Internet is wide network of computers and is open for all. |
Intranet is also a network of computers designed for a specific group of users. |
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2. |
Internet itself contains a large number of intranets. |
Intranet can be accessed from internet but with restrictions. |
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3. |
The number of users who use internet is unlimited. |
The number of users is limited. |
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4. |
The visitors traffic is unlimited. |
The traffic allowed is also limited. |
|
5. |
Internet contains different source of information and is available for all. |
Intranet contains only specific group information. |
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6. |
Content in the network is readily accessible by everyone who is connected. |
The content in the network is accessible only to members of the organization. |
|
7. |
Internet is a means of sharing information throughout the world. |
Intranet is a means of sharing sensitive or confidential information throughout the organization. |
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8. |
Internet is the largest network in as far as the number of connected devices is concerned. |
It is a small network with a few numbers of connected devices. |
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9. |
Users have unrestricted access and can access internet anonymously. |
An intranet may be accessible from the internet, but it is protected by a password and accessible only to authorized users. |
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10 |
Security is dependent of the user of the device connected to network. |
Security of the network is enforced through a firewall. |
ISP (Internet Service Providers):
The term Internet service provider (ISP) refers to a company that provides individuals and organizations access to the internet and other related services.
The ISP connects your personal computer, notebook, PDA, mobile device, game station, etc. to the Internet. Another name for ISP is IAP, or Internet Access Provider. ISPs make it possible for their customers to surf the web, shop online, conduct business, and connect with family and friends. ISPs may also provide other services including email services, domain registration, web hosting etc.
URL:
URL stands for “Uniform Resource Locator”. It is defined as the global address of documents and other resources on the World Wide Web. We all use URLs to visit webpages and other resources on the web. The URL is an address that sends users to a specific resource online, such as a webpage, video or other document or resource.
A Uniform Resource Locator (URL) is a set address for locating a unique resource on the internet, such as a file or an app. Uniform Resource Locators or URL’s are the standard way of locating and retrieving information on the World Wide Web. They tell the browser what piece of information to retrieve how to get to it and what protocol to use in the process. URL can be thought of as a postal address for the web. They specify where pages, files and other pieces of information are located, making it possible for browsers to find and display or even to download that information. URLs are read from left to right, just like a telephone number.
A URL is a formatted text string used by web browsers, email clients and other software to identify a network resource on the internet. Network resources are files that can be plain web pages, other text documents, graphics or programs. It is recognizable for users as the string of text which is shown in the browser address bar of every web page, or which links a user to another internet location.
Components of a URL:
The URL consists of four parts:
Protocol: The application level protocol used by the client and server, e.g., HTTP, FTP, and telnet. It defines a network protocol to be used to access a resource. These strings are short names followed by the three characters ‘://’ (a simple naming convention to denote a protocol definition). Typical URL protocols include http://, ftp: // , telnet:// etc.
Hostname: It identifies a computer or other network device such as DNS domain name (e.g., www.yahoo.com) or IP address of the server.
Port: The TCP port number that the server is listening for incoming requests from the clients.
Path and file name: The name and location of the requested resource, under the server document base directory.
For example, in the URL http://www.yahoo.com/docs/index.html, the communication protocol is HTTP; the hostname is www.yahoo.com. The port number takes default number, which is TCP port 80 for HTTP. The path and file name for the resource to be located is “/docs/index.html”.
Email:
E-mail or Electronic mail is one of the most widely used services of the internet. It can be defined as the exchange of messages and computer files between computers over a computer network. This network can be as small as a Local Area Network (LAN) or it can be as large as the Internet that spans the world. Electronic mail or e-mail is without doubt the most commonly used Internet service.
E-mail service allows a user to send messages (text, pictures, sound files, program files or animated movies) over the internet to another user in any part of the world. With e-mail, sending and receiving messages has become an easy task. It simply involves opening of connection for communication, sending data and finally closing down the connection. All the users who send e-mail must have an e-mail address (E-mail Id).
Some of the popular e-mail service providers are:
File Transfer Protocol (FTP):
File Transfer Protocol (FTP) is a standard network protocol used to transfer files from one computer to another (typically from your computer to web server ) over internet. FTP is most commonly used to download a file from a server using the internet or to upload a file to a server (e.g., uploading a web page file to a server).
Files can be transferred in either direction. “Downloading” refers to a transfer of a file from a remote computer to your computer. “Uploading” refers to a transfer of a file from your computer to a remote computer.
FTP is built on client-server architecture and utilizes separate control and data connections between the client and server.It is preferred method of exchanging files because it’s faster than other protocols like HTTP or POP. If you need to exchange large files, you should consider FTP. FTP data is sent and received through computer port 21 and under the TCP protocol. The transfer is asynchronous, meaning not at the same time and therefore faster than other protocols.
In order to upload or download a file by FTP, we need to do four things:
1. Login into a remote computer that has been configured as an FTP server.
2. Submit a username and a password to gain access to the remote system.
3. Change to the particular directory on the remote system which contains the file you wish to download or upload.
4. Transfer the file to or from the system
Objectives of FTP:
· To promote sharing of files (computer programs and/or data).
· To encourage indirect or implicit (via program) use of remote computers.
· To shield a user from variations in file storage systems among hosts, and
· To transfer data reliably and efficiently.
Internet Chatting:
Today chatting is one of the most popular activities on the internet. Internet chatting may refer to any kind of communication over the internet that offers a real-time transmission of text, picture, audio or video messages between two or more users in chat rooms. Chatting on the internet is a popular way for individuals, families and business to stay connected.
World Wide Web:
Tim Berners-Lee is widely known as the father of the World Wide Web. The World Wide Web, abbreviated as WWW and commonly known as the web, is a system of interlinked hypertext documents accessed via the Internet. World Wide Web is a set of programs, standards and protocols that allows the text, images, animations, sounds, videos to be stored and accessed and linked together in the form of websites. Basically, WWW is a collection of millions of web pages stored in thousand of computers (servers) all over the world.
World Wide Web and the internet are not the same, but they are related and interdependent. The web resides “on top of” the internet. World Wide Web is a huge collection of “pages” of information linked to each other around the globe. Each page can be a combination of text, pictures, audio clips, video clips, animations and other electronically presentable material.
The web is actually a superset of the internet. It can be thought of as a graphical interface to the internet, providing a revolutionary way of accessing information scattered across millions of computers around the world.
Difference between Internet and WWW:
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S. No. |
INTERNET |
WWW |
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1 |
Internet is a global network of networks. |
WWW stands for World Wide Web |
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2 |
Internet is a means of connecting a computer to any other computer anywhere in the world. |
WWW is a collection of information which is accessed via the internet |
|
3 |
Internet is infrastructure |
WWW is service on top of that infrastructure |
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4 |
Internet can be viewed as a big book-store. |
Web can be viewed as collection of books on that store. |
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5 |
At some advanced level, to understand we can think of the internet as hardware. |
At some advanced level, to understand we can think of the WWW as software. |
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6 |
Internet is primarily hardware-based |
WWW is more software oriented as compared to the internet. |
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7 |
It is originated sometimes in late 1960s |
English scientist Tim Berners-Lee invented the world Wide Web in 1989. |
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8 |
The first version of the internet was known as ARPANET |
In the beginning WWW was known as NSFNET |
|
9 |
Internet uses IP address |
WWW uses HTTP |
Web Pages:
The term “page” refers to nothing more than a World Wide Web document. A web page is much more like a word processing document than a printed page, especially the way it is viewed.
A webpage is a web document that is accessible through the internet using a web browser like internet explorer. A webpage is accessed by entering a URL (Uniform Resource Locator) addresses in the Address field of web browser. A webpage may contain text, graphics, and hyperlinks to other web pages and files.
Web Site:
A website is composed of a group of web pages linked together. It is a central location that contains more than one web page.
Web Server:
Web server refers to hardware (the computer) or the software (the computer application) that is used to deliver web pages to clients. A web server does a great deal of work in making web pages and sites available to browsers.
Web pages must reside somewhere on the internet in order to be accessed with a browser and a server is where we will find them. There are literally millions of Web servers on the internet, each of which may be home to thousands of web pages. The server is responsible for delivering these pages to web browser when it asks for it, i.e. it “serves” web pages to browsers.
A large company may have its own server, but usually individual and small companies rent or lease space on the server provided by an Internet Access Company. Without servers there would be no web.
Web Browser:
A web browser is a software application for retrieving, presenting and traversing information resources on the World Wide Web. With a web browser, one can view web pages that may contain text, images, videos, and other multimedia and navigate between them by using hyperlinks. Hyperlinks present in resources enable users to easily navigate their browsers to related resources.
A web browser or simply “browser” is an application used to access and view websites. Common web browsers include Microsoft Internet Explorer, Mozilla Firefox, Apple Safari, Google Chrome, and Opera.
Function of Web Browser:
The primary function of a web browser is to render HTML, the code used to design or “mark up” webpages. Each time a browser loads a webpage it processes the HTML, which may include text, links and references to images and other items, such as cascading style sheets and JavaScript functions. The browser processes these items, and then renders them in the browser window.
Early web browsers, such as Mosaic and Netscape Navigator were simple applications that rendered HTML processed from input and supported bookmarks. As websites have evolved, so have web browsers requirements.
Todays browsers are far more advanced, supporting multiple types of HTML (such as XHTML and HTML5), dynamic JavaScript and encryption used by secure websites.
The capabilities of modern web browsers allow web developers to create highly interactive websites. For example, Ajax enables a web browser to dynamically update information on a webpage without the need to reload the page. Advances in CSS allow browsers to display a layouts and a wide array of visual effects. Cookies allow browsers to remember settings for specific websites.
While web browser technology has come a long way since Netscape, browser compatibility issues still remain a problem. Since browsers use different rendering engines, websites may not appear the same across multiple browsers. In some cases, a website may work fine in one browser, but not function properly in another. Therefore, it is smart to install multiple browsers on your computer so you can use an alternate browser if necessary.
Search Engine:
A search engine is a software tool or a website that allows people to find information on the World Wide Web. When we enter a keyword into the search engine, the search engine will look through the billions of web pages to help us find the ones that we are looking for. Today there are thousands of different search engines available on the internet, each with their own abilities and features.
Search engines allow users to search the internet for content using keywords. Although the market is dominated by a few, there are many search engines that people can use. Google, Excite, Lycos, AltaVista, Infoseek and Yahoo are all search engines.
Introduction to E-Commerce
E-Commerce Meaning:
E-commerce stands for Electronic Commerce. It refers to buying, selling, dealing, ordering and paying for the goods and services with the use of electronic systems such as internet. It is “doing business online”.
The evolution of e-commerce has significantly transformed the way companies are doing business. It includes any commercial activity that takes place directly between a business, its partners, or its customers through electronic communication and digital information processing technology.
E-commerce is a merchandising tool in which buyers participate in all stages of purchasing processes electronically rather than in a physical store. It is a online commercial transaction in which the seller can communicate with the buyer without having a face to face interaction.
E-commerce can be defined as: It is a process of buying and selling of products, services and information over electronic networks, including the internet or mobile applications.
E-commerce is a modern business methodology that addresses the needs of organizations, merchants, and consumers to cut costs while improving the quality of goods and services and increasing the speed of service delivery. E-commerce offers opportunity to perform profitable activities online. Besides buying or selling, it also facilitates the following services and capabilities:
· Publishing and distributing information
· Providing customer service
· Gathering information
· Providing seller support
· Collaborating with others.
· Communicating within organizations
Objectives of E-Commerce
The various objectives that businesses typically strive to accomplish through e-commerce are:
· To provide online customers with quick delivery of products or services.
· To gain access to a world wide market
· To increase sales in existing market and opening new market
· To develop business opportunities over the internet
· To improve productivity and competitiveness
· To improve customer experience and satisfaction
· To offer more customizable products
· To keep the virtual shop open 24X7