A network can be defined as a group of computers and other devices connected in some ways so as to be able to exchange data.
-Each of the devices on the network can be thought of as a node; each node has a unique address.
-Addresses are numeric quantities that are easy for computers to work with, but not for humans to remember.
-Some networks also provide names that humans can more easily remember than numbers.
Example: www.cmscomputer.in, corresponding to the above numeric address.
Consists of 4 bytes separated by periods
-The R first bytes (R= 1,2,3) correspond to the network address;
-The remaining H bytes (H = 3,2,1) are used for the host machine.