This document provides an overview of basic internet concepts and HTML. It defines the internet as a network of networks that connects computers globally using a client-server model. It describes common internet protocols like HTTP, HTTPS, FTP. It also explains basics of HTML like tags, structure, editors and how HTML pages are executed in web browsers to display content. The document serves as an introduction to fundamental internet and web technologies.

1. COM 311 – AGRO-INFORMATICS (1 + 1)
LECTURE 3 – Internet – Basic – Application - HTML
Prepared by
Mr. B. Venujayakanth, M.Sc (Agri.) NET.,
Assistant Professor
(Agricultural Statistics)

2. INTERNET
• It is the network of computers or network of network.
• It links different types of computer across the world to
have a common platform for communication.
• It is the largest WAN (Wide Area Network).
• Every computer in the internet is called host.

3. How INTERNET works..???
• User in the Internet is called as Client and the
computer which provide service to the user is called
server.
• So Client in this model is known as frontend and
server is known as backend.
• It works by using Client-Server Model.
User – Browser Internet server

4. PROTOCOL
COMMUNICATION OR NETWORK PROTOCOL
• It is the set of rules that govern transmission of data
over network.
INTERNET PROTOCOL
• It is the set of rules that govern transmission of data in
the internet.
• Protocol is a set of formal operating rules or
procedures that govern a given process.

5. HTTP – Hyper Text Transfer Protocol
• Hypertext documents are the documents through which
user in the internet can navigate from one page to
another in internet.
• It enables this by using a series of link.
• The link called as hyperlink.
FTP – File Transfer Protocol – The protocol that is
followed to move a file from one computer to another
computer in Internet
• The protocol that is followed to transfer Hypertext
documents in the Internet.

6. HTTPS – Hyper Text Transfer Protocol Secure
• In HTTPS the data is encrypted and send in Internet.
• This features not allow hackers to read any information.
• Online transaction and many other websites now using
HTTPS for secure data transfer.
• It is similar to HTTP but it is secured version

7. WWW – World Wide Web
• It was created by Tim Bernes Lee in 1989
• It is the user part of Internet. i.e. WWW comes under
Internet.
• Internet is a structure, where WWW uses to organize and
accesses information.
• It refers to the set of all resources and the users on the
Internet that are using hypertext Transfer Protocol.

8. WWW BROWSERS OR WEB BROWSER
• Since Internet uses Client Server Model.
• To make a user computer as a web client one needs Web
Browser.
Example: Internet Explorer, Google Chrome, Mozilla
Firefox, Netscape etc.
• It is a software which enables the user to visit and access
information from server computer site by specifying its
URL address (E.g.: ww.tnau.ac.in).

9. URL – UNIFORM/ UNIVERSAL RESOURCE LOCATOR
• It specifies the unique address for a file that is accessible on
the Internet.
• Example: http://www.tnau.ac.in
• If one wants to see rank list of UG admission on the above
website, then the URL will be like
http://www.tnau.ac.in/ugadmission.html
• It is an addressing scheme which WWW browsers use to
locate sites on the Internet.

10. http://www.tnau.ac.in/ugadmission.html
Protocol
Domain/server
File name
Note: In URL blank spaces are not allowed, it maybe either filled
by %20, & etc.
Note: In URL everything after the “?” are variables.
Path of the file
is represented
after domain
name.

11. TYPES OF URL
• Absolute URL – URL which specifies all the three fields
(Protocol, domain and path)
Example: http://www.tnau.ac.in/ugadmission.html
• Relative URL – URL which specifies only the domain name
Example: tnau.ac.in or www.tnau.ac.in
There are basically two types of URL
1. Absolute URL and
2. Relative URL

12. IP(INTERNET PROTOCOL) ADDRESS
• There are two types of IP address : IPv4 and Ipv6
• DNS - Domain Name System is a service that automatically
convert domain name into IP addresses.
Example: www.google.com is 74:125:224:74
• It is the unique address allotted to computing devices such
as computer, routers, printers, modems etc. that are
connected on the Internet.

13. HTML
• Unlike C, C++, JAVA, it is not used to write any software,
rather it is used to create web pages.
• It was created by Tim Bernes Lee in 1991.
• Most of the documents in the webpage are written by using
HTML
• It stands for Hyper Text Mark-up Language.
• It is a Tag based or Script level programming language.

14. Why the name HTML..???
• Hyper – Where it create link to the other page or website
etc.,
• Text – write by using English Text.
• Mark-up – It is written by using TAGs (‘< >’), which
mark the text in the program.
• Language – Used for Communication in the Internet.

15. EDITOR AND FILE EXTENSION
• HTML is written by using a Editor.
• The commonly used editor for writing is Notepad or
Notepad++ etc.
• Once it is written, the file is save in a extension named
HTML or HTM.
• i.e. .html or .htm are file extension of HTML files.

16. EXECUTION or OUTPUT
• HTML is executed in Web browser.
• The output of the written HTML language is executed in
anyone of the web browser such as Internet Explorer,
Mozilla, Google Chrome etc.

17. BASIC SYNTAX OF HTML
<!DOCTYPE html>
<html>
<head> <title> ………. </title> </head>
<body> ………
………
</body>
</html>
• Each element written inside the < …. > symbol is called Tag.
• Each element have Closing Tag consist of ‘Backslash’. opening
<…> and Closing Tag </….>.
• The page that is inside the body tag is visible on the web page.

18. BASIC TAGS HTML
• <html> - basic tag to start.
• <body> - it is the main content of the page that is visible.
• <head> - To create header.
• <Title> - To create title.
• <h1> to <h6> - Used to write heading in Bold.
• <p> - used to write paragraph.
• </br> - used to break the line.
• <table> - Used to create Table.
• <tr> - used to write table row.
• <td> - used to write table data.
• <th> - used to write table heading or column.

19. BASIC TAGS HTML
• <ul> - used to write unordered list
• <li> - used to list the elements.
• <a> - anchor tag - used to create hyperlink that links one page to
another page
• Href – variable that is used inside the anchor tag for navigation
purpose.
• <hr> - used to create horizontal line
• <img> - used to put an image in html.
• <marquee> - used to write Scrolling text in horizontal or vertical
direction
• <Sup> - To create super script
• <sub> - To create subscript.

20. THANK YOU