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 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:
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
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 |
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. |
2. |
Internet
itself contains a large number of intranets. |
Intranet
can be accessed from internet but with restrictions. |
3. |
The
number of users who use internet is unlimited. |
The
number of users is limited. |
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. |
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. |
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. |
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. |
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 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:
a 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.
b 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.
c 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, you 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.
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:
S.
No. |
INTERNET |
WWW |
1 |
Internet
is a global network of networks. |
WWW
stands for World Wide Web |
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 |
4 |
Internet
can be viewed as a big book-store. |
Web
can be viewed as collection of books on that store. |
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. |
6 |
Internet
is primarily hardware-based |
WWW
is more software oriented as compared to the internet. |
7 |
It
is originated sometimes in late 1960s |
English
scientist Tim Berners-Lee invented the world Wide Web in 1989. |
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 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 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, Yahoo, Excite, Lycos, AltaVista, Infoseek 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:
· 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
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