IP address

IPV4 - 32 bit address
IPV6 - 128 bit address

Public addresses

Format : x.x.x.x (where each 'x' is a 8 bit value)
IPV4 is divided into the following 5 classes, which is based on the decimal value of the first octet

Class A :     0 - 126.x.x.x (first octet forms network ID-NID and last three octets forms host ID-HID)
Class B : 128 - 191.x.x.x (first 2 octets forms NID and last 2 octets forms HID)
Class C : 192 - 223.x.x.x (first 3 octets forms NID and last octet forms HID)
Class D : 224 - 239.x.x.x (used for multicast)
Class E : 240 - 255.x.x.x (used for research purpose)

Private addresses

Class A
Range : 10.0.0.0 - 10.255.255.255
Total number of networks : 1

Class B
Range : 172.16.0.0 - 172.31.255.255
Total number of networks : 16

Class C
Range : 192.168.0.0 - 192.168.255.255
Total number of networks : 256