Why we need network.

Key points to remember:-------------
1.It is the group of computer.
2.To share data and information.
3. To save time and money.
4. It use various application to do these above task. like Web browser,email,database and collaboration
How It work.
To Understand working of computer network.Just focus on terminology
1.LAN
2 Broadcast Domain.
3.Collision Domain
4. Network segmentation
5.OSI Model
6.TCP/IP model.

What is LAN.
1.It is the type of network which is situated in a single physical location.Like one building ,school etc.
2.It is base of WAN.
3.It Works on technology like Ethernet,token ring fddi etc. out of which Ethernet is most popular, because of it is easy to implement and  understand.

What is Broadcast Domain:-----

1.It is the area through which all the devices can listen and receive the data .

2. This is the message from single point to all directions.

3.For eg.: message from TV and radio.

4.Network device like switch is a single broadcast domain

5.Switch separate the collision domain. and provide network segmentation.

6.router separate the broadcast domain.

What is Collision Domain:---------

1.It is area where all devices try to access the same media.like single cable.

2.when multiple devices accessing the same media there may be chances of collision (data crash)

3.When collision occur no device can get the data.

4. This problem arise the need of new rule. so that we can protect data from crashing or conflicting.

5.Network device hub is called single collision device.

6.This device operate on the rule CSMA/CD.(carrier sense multiple access/collision detection.)

7.This rule work on the principle that one time only one device can transmit the data. in order to avoid data collision.

8.This communication method is called as Half duplex.(means one time only one device can transmit.like walky talky).