IP Address – IP (Internet Protocol) is a unique number for a computer or device on a TCP/IP network. The format of an IP address (IPv4) is a 32 bits address, for example 192.168.0.10
IP addresses are managed and created by the Internet Assigned Numbers Authority (IANA).
IPv4 divided to 3 classes of networks:

Class A: with 16,777,214 numbers of hosts.
Class B: with 65,534 numbers of hosts.
Class C: with 254 numbers of hosts.