The document defines and compares Internet, Intranet, and Extranet. It explains that Internet is a worldwide network accessible to the public, Intranet is a private network within an organization, and Extranet extends an organization's Intranet to selected partners and suppliers. It also covers topics like IP addresses, domain name systems, protocols for email (SMTP), file transfer (FTP), and more.

1. Internet, Intranet
& Extranet
Presented By:
Asmita Singh
Asst. Professor
(Swami Keshwanand Rajasthan
Agriculture University, Bikaner)

2. Internet
 Internet is defined as an Information super Highway, to access
information over the web. However, It can be defined in many
ways as follows:
 Internet is a world-wide global system of interconnected
computer networks.
 Internet uses the standard Internet Protocol (TCP/IP).
 Every computer in internet is identified by a unique IP
address.
 IP Address is a unique set of numbers (such as
110.22.33.114) which identifies a computer location.
 A special computer DNS (Domain Name Server) is used to
give name to the IP Address so that user can locate a
computer by a name.

3.  For example, a DNS server will resolve a
name http://www.tutorialspoint.com to a particular IP address to uniquely
identify the computer on which this website is hosted.
 Internet is accessible to every user all over the world.

4. Intranet
 The term Intranet is derived from two words: ‘Intra’ which
means within and ‘net’ which means group of interconnected
computers.
 Intranet is system in which multiple PCs are networked to
be connected to each other. PCs in intranet are not available
to the world outside of the intranet.
 Usually each company or organization has their own
Intranet network and members/employees of that company
can access the computers in their intranet.
 Each computer in Intranet is also identified by a IP
Address, which is unique among the computers in that
Intranet.

7. EXTRANET
 is an intranet for outside authorized users
using same internet technologies. The outside
users are trusted partners of the organization
who have access to information of their
interest & concern.
 extends the intranet concept to provide a
network that connects a company’s network to
the networks of its business partners, selected
customers, or suppliers.

9. Domain Name Systems
 If you've ever used the Internet, it's a good bet that you've
used the Domain Name System, or DNS, even without
realizing it.
 DNS is a protocol within the set of standards for how
computers exchange data on the Internet and on many
private networks, known as the TCP/IP protocol suite.

10.  Its basic job is to turn a user-friendly domain
name like "howstuffworks.com" into
an Internet Protocol (IP) address like
70.42.251.42 that computers use to identify
each other on the network. It's like your
computer's GPS for the Internet.

12. INTERNET PROTOCOL (IP)
 IP address is a numerical label assigned to each
device connected to a computer network that uses
the Internet Protocol for communication.
 An IP address serves two principal functions: host
or network interface identification and
location addressing.
 Your IP can change with the change in network.

13.  It is a 32 bit address ( binary address) often written in
4 groups of 3 decimals each i.e 192.168.1.2
 This is a logical address for your device through
which it communicates to the outside world.

14. MEDIA ACCESS CONTROL
(MAC ADDRESS)
 Mac address is your machine address . This address
will never change & is the unique machine address
given to your device .
 Your device will have communication with the
local area network or any network using this
address.
 Once you use the network your mac address is
stored in the network table so that network does not
have to search your mac address again and again.

15.  It is 48 bits (6 bytes) hexadecimal address.
 MAC address is assigned by the manufacturer
of NIC ( Network Interface Card).
 NIC is a chip installed in the computer that lets
you connect your device with any network.
 For example, consider a network adapter with
the MAC address "00-14-22-01-23-45."

16. Simple Mail Transfer Protocol
(SMTP)
 The Simple Mail Transfer Protocol (SMTP) is used to transfer
electronic mail from one user to another. This task is done by means
of email client software (User Agents) the user is using.
 User Agents help the user to type and format the email and store it
until internet is available.
 When an email is submitted to send, the sending process is handled by
Message Transfer Agent which normally comes inbuilt in email client
software.
 Message Transfer Agent uses SMTP to forward the email to another
Message Transfer Agent (Server side).
 Client software uses Internet Message Access Protocol (IMAP) or POP
protocols to receive emails.

17. POP/
IMAP

18. FTP
 The File Transfer Protocol (FTP) is the most
widely used protocol for file transfer over the
network. FTP uses TCP/IP for communication.
 The client requests the server for a file. When the
server receives a request for a file, it opens a TCP
connection for the client and transfers the file.
 After the transfer is complete, the server closes
the connection. For a second file, client requests
again and the server reopens a new TCP
connection.