Just like every home has an address every node in the network has a unique address. IP address is the address used for communication between the computers at the network layer level. Every computer linked to the web will be allotted a 32 bit IP address during start up. The IP address can be broadly classified as two types namely classful and classless addressing. Let us take a look at the classful addressing
Class A can be allocated to large size universal networks and they can accommodate a whopping 16,777,216 computers.
Class B addresses can incorporate 65,536 hosts and are most commonly allocated for intermediate size networks like MAN etc.
Class C addresses can support only 256 hosts and they are allocated to many small organizations with lower number of terminals.
Class D address serve as multicast addresses which are used to send data to several nodes at the same time.
Class E addresses are reserved for future use. Recently Classless addresses are being used. IP addresses are often used conservatively with the help of techniques like Network Address Translation(NAT) and Subnetting.