Inet address is one of identifier. This is used denote the 
IP address of the networked system.

Every computer connected to a network has an IP address.An
IP address is a number that uniquely identifies each
computer on the Net.An IP address is a 32-bit number.

Inet address identifies the IP address of any system
conneted to the network ,and this identifier is used in java
,and it  is something similar  to datatypes in c  and c++ .

It is mensioned the system address

InetAddress is a class used to find the ip address of a host
in a network.

This InetAddress is divided into two types,
1)Inet4address for the ip version 4(ipv4)=Which has 32bit ip
address
2)Inet6address for the ip version 6(ipv6)=Which has 128bit
ip address

There are subclasses & abstract in the InetAddress.

An Internet Protocol (IP) address is a numerical label for
devices  used  in a computer network. An IP address serves
two principal functions in networking: host identification
and location addressing.it is 32 bit for ip version 4 and
128 bit forip version 6.

Inet address is a class encapsulating both this ip address
and the domain name for this address.This class can be used
for getting the ip address of systems by providing the name
and vice versa.This is done by some functions in the class
such as getaddress(),getbyname()