An Internet Protocol (IP) address is a numerical label that is assigned to devices participating in a computer network that uses the Internet Protocol - or in plain English:
An IP address is the location of a computer on the internet
For example: 123.45.67.89
These four numbers are referred to as "octets". The first octet is the first number of the IP address (123), and the fourth octet is the fourth or last number of the IP address (89).
A domain name represents what is present at an IP address but the IP address represents exactly where it is on the internet.
There are several categories or types of IP addresses:
Static IP address means that the address never changes as long as you stay with the same provider or same server.
Dynamic IP address means that the address can change from time-to-time as it is allocated to different users.
Public IP address means that the address can be visited from any computer in the world.
Private IP address means that the address can only be used by those on the same network.
Shared IP address means that other people also use the address for their connection or sites.
Dedicated IP address means that no one else uses your address for their connection or sites.