12-IP Notes
12-IP Notes
12-IP Notes
Introduction to Internet:
The internet is composed of a large number of smaller interconnected networks. These networks may link tens,
hundreds, or thousands of computers. The Internet is the global network of computing devices including desktop,
laptop, servers, tablets, mobile phones, other handheld devices as well as peripheral devices such as printers,
scanners, etc. Today, smart electronic appliances like TV, AC, refrigerator, fan, light, etc., can also communicate
through the Internet.
History of Internet: US defense department had sponsored a project ARPANET (acronym for Advanced Research
Project Agency NETwork) in the year 1969. It was a first and a small project run through internet technology.
NSFnet was created by the National Science Foundation which was more capable than ARPANET. The linking of
these two and some other networks was named INTERNET.
Advantages of Internet:
1. Easy to communicate.
2. Cost effective.
3. Global reach of people and products.
4. Publishing documents on internet saves paper.
5. An effective tool to grow business.
Disadvantages:
1. Increase of cyber fraud.
2. Risk of hacking the important info.
3. Virus may be spread across the PCs connected to internet.
4. Irrelevancy of information.
5. Loss of social skills.
6. Increase of cybercrimes.
Applications of Internet
Following are some of the broad areas or services provided through Internet:
• The World Wide Web (WWW)
• Electronic mail (Email)
• Chat
• Voice Over Internet Protocol (VoIP)
1. HTML
2. URL
3. HTTP
1. HTML: HyperText Markup Language or HTML is a language which is used to design standardised Web Pages so
that the Web contents can be read and understood from any computer across the globe.
2. URL: URL is Uniform Resource Locator and provides the location and mechanism (protocol) to access the
resource. Example of URL is:
Domain name
https://cbseacademic.nic.in/SQP_CLASSXII_2021-22.html
URL
URLs are two types:
A. Absolute URL: These URL contains both the domain name and directory/page path. It comes with
the following syntax:
Protocol://domain name/directory/file path
B. Relative URL: The relative URL tells a URL location in terms of the current location. Relative path
is used to reference a given link of a file that exists within the same domain.
3. HTTP: The Hypertext Transfer Protocol is a set of rules which is used to retrieve linked web pages across the web.
It’s more secure and advanced version is HTTPS.
Following are some of the common facilities available for an email user:
1. Creating an email, attaching files with an email, saving an email as draft for mailing later. Creating email is also
termed as composing.
2. Sending and receiving mail. Same email can be sent to multiple email addresses, simultaneously.
3. Sending the copy of mail, as carbon copy (cc) or blind carbon copy (bcc).
4. Forwarding a received email to other user(s)
5. Filtering spam emails
6. Organizing email in folders and sub folders
7. Creating and managing email ids of the people you know.
8. Setting signature/footer to be inserted automatically at the end of each email
Chat
Chatting or Instant Messaging (IM) over the Internet means communicating to people at different geographic
locations in real time through text message(s). Applications such as WhatsApp, Slack, Skype, Yahoo Messenger,
Google Talk, Facebook Messenger, Google Hangout, etc., are examples of instant messengers. Some of these
applications support instant messaging through all the modes — text, audio and video.
VoIP
Voice over Internet Protocol or VoIP allows us to have voice call (telephone service) over the Internet, i.e., the voice
transmission over a computer network rather than through the regular telephone network. VoIP works on the
simple principle of converting the analogue voice signals into digital and then transmitting them over the
broadband line. The only disadvantage of VoIP is that its call quality is dependent on Internet connection speed.
Slow Internet connection will lead to poor quality voice calls.
Web Server:
Webserver is a computer that stores the websites and respond to the request made by web browser. A web server
is also called WWW. Web Server A web server is used to store and deliver the contents of a website to clients such
as a browser that request it. A web server can be software or hardware. The web browser from the client computer
sends a request (HTTP request) for a page containing the desired data or service. The web server then accepts,
interprets, searches, and responds (HTTP response) to the request made by the web browser. The requested web
page is then displayed in the browser of the client.