Internet

1. Internet
The internet is a network of networks.A global
communications system that links together thousands of
individual networks. As a result, virtually any computer on
any network can communicate with other computer on any
other network. These connections allows users to exchange
messages ,to communicate in real time (seeing messages
and responding immediately), to share data and programs,
and to access limitless stores of information.

2.  The internet has become so important that its use is considered an
essential part of the computer use. In other words, mastering the
internet is one of the first things you should do, if you want to get
the most from your computing experience.
 The seeds of the internet were planted in 1869 by the Advance
Research Projects Agency (ARPA) of US. Department of defence
began connecting computers at different universities and defence
contractors. The resultant network was called ARPANET. The goal
of this early project was to create large computer network with
multiple paths in the form of telephone lines that could survive a
nuclear attack or a natural disaster such as earthquake. If one part
of the network were destroyed, other parts of network would
remain functional and data could continue to flow through the
surviving lines.

3. APRA had second important reason for creating such a network.
That is ,it would allow people in remote locations to share scarce
computing resources. By being part of the network, these users
could access faraway systems such as government mainframes or
universities owned supercomputers and conduct research or
communicate with other users.

4. The Internet’s Major Services
 The World Wide Web
 Electronic Mail
 News
 File Transfer Protocol
 Chat
 Instant messaging
 Online services
 Peer to peer services

5. World Wide Web
 The World Wide Web (WWW)
Developed in 1993 by Tim-Berners Lee
Allowed connection of documents
Required a browser to read documents

6. Electronic Mail (E.Mail)
Electronic mail (e-mail)
Instantaneous transmission of documents anywhere in the
Faster way to communicate than postal.
 Easy to access
 Its ability to attach data files and program files to messages
You may be able to exchange audio and video messages
with someone else.

7. NEWSGROUP
 News group are relatively fast way to distribute
information to a potentially interested readers,
and they allow people to discuss topics of
common interest.
 They also can be a convenient channel for
finding answers to questions.

8. File Transfer Protocol (FTP)
 FTP is an internet tool used to copy files
from one computer to another.
 FTP sites provides access to many
different types of files
 FTP site is a collection of files, including
data files or program files, that are house
on an FTP Server.

9. Public real time conversation
 Instant messaging
Private real time conversation
 Peer-to-peer services
Allows sharing of files among users
Napster and Kazaa are examples
Illegal to share copyrighted material
CHAT

10.  Stands for "Peer to Peer." In a P2P network, the "peers" are computer systems
which are connected to each other via the Internet. Files can be shared directly
between systems on the network without the need of a central server. In other
words, each computer on a P2P network becomes a file server as well as a client.
 The only requirements for a computer to join a peer-to-peer network are an
Internet connection and P2P software. Common P2P software programs include
Kazaa, Limewire, BearShare, Morpheus, and Acquisition. These programs connect
to a P2P network, such as "Gnutella," which allows the computer to access
thousands of other systems on the network.
 Once connected to the network, P2P software allows you to search for files on
other people's computers. Meanwhile, other users on the network can search for
files on your computer, but typically only within a single folder that you have
designated to share. While P2P networking makes file sharing easy and
convenient, is also has led to a lot of software piracy and illegal music downloads.
Therefore, it is best to be on the safe side and only download software and music
from legitimate websites.

11. Internet Service Provider (ISP)
Company that provides Internet access
Dialup
Connects to Internet through phone line
Modem connects to the phone line
Slow connection

12. Dialup
 High-speed access
Connect through a special line
2 – 25 times faster than dialup
DSL, Cable, are common

13. The Internet allows accessing resources
The Web simplifies the Internet
The Web connects documents
Hypertext creates links between documents
Documents are stored on a web server
HTTP delivers documents

14. Web site is a collection of documents
Document is a web page
Pages are published to the web
Hypertext Markup Language
Creates web pages
Describes how pages should look
Content enclosed in tags
<tag>content</tag>

15. Browsers
Read and translate the HTML
Display web content
Uniform Resource Locator (URL)
Address of a web page

16. Helper applications
Plug-ins
Enhance a browser’s functionality
Streaming audio and video
Sends the file in small chunks
Chunks downloaded while others play

17. Streaming Audio

18. Site searches
Large sites have an internal search
Metasearch sites
Search several web sites at once
Sponsored links
Sites pay for better search results

19.  A Metasearch engine is a search tool that uses other search
engines’ data to produce their own results from the Internet.
Metasearch engines take input from a user and simultaneously
send out queries to third party search engines for results.
Sufficient data is gathered, formatted by their ranks and
presented to the users.