Ip address??

Ip stands for Internet protocol address it is logical it it is uniquely identify the network of the connection it can be changed it is public or private it is static user config it remotely dynamic provided by DHCP(DYNAMIC HOST CONFIGURATION PROTOCOL) ip has 2 version IPV4 it's of 32bit or 4 byte IPV6 it's of 128 bit IP has 2parts Host part and network Part.

 Class-A 

Public IP Range: 1.0.0.0 to 127.0.0.0

Private IP Range:10.0.0.0 to 10.255.255.255

Class-B

Public IP Range: 128.0.0.0 to 191.255.0.0

Private IP Range-172.16.0.0 to 172.31.255.255

Class-C

Public IP Range: 192.0.0.0 to 223.255.255.0

Private Ip range-192.168.0.0 192.168.255.255

Class-D for multicasting purpose send a data to different server

Range: 224.0.0.0 to 239.255.255.255

Class-E for future purpose or scientific research 

Range: 240.0.0.0 to 255.255.255.255

Link local or APIPA RANGE - 169.254.0.1-169.254.255.254, 

Subnet mask of APIPA-255.255.0.0

What is subnet mask??

A subnet mask is logically subdivision of a IP address which shows the network bits of an IP address.