Essential Concept

1.Computer network

A computer network is a group of two or more computers linked together so that
communication between individual computers is made possible. Some of the common types computer  network include:

2.Local Area Network (LAN)

This is a type of computer network where interconnected computers are situated very
close to each other say for example, inside the same building.

3.Wide Area Network (WAN)

This is a type of computer network where interconnected computers are separated by a large distance (a few km to few hundreds of km) and are connected using telephone linesvor radio waves.

4.Internet

The Internet is the largest network which interconnects various LANs and WANs. It is a global system of various interconnected computer networks belonging to
government or private organizations.

5.Network host

A network host (or simply referred to as a host) can be any computer or network device connected to the computer network. This computer can be a terminal or a web server offering  services to its clients.

 6.Internetrotocol (IP Address)

An Internet Protocol address (IP address) is a unique number assigned to each computer or device (such as printer) so that each of them can be uniquely identified on the network.

Types of IP Address:

Private IP Address:
A private IP address is the one that is assigned to a computer on the
Local Area Network (LAN). A typical example of private IP address would be something like 192.168.0.2

Public IP Address: A public IP address is the one that is assigned to a computer
connected to the Internet. An example public IP address would be something like:
59.93.115.125
In most cases a computer gets connected to the ISP network using a private IP. Once a
computer is on the ISP network it will be assigned a public IP address using which the communication with the Internet is made possible.