IP – Internet Protocol
IP or IP address is a number i.e. ( 216.58.216.165 ) used to indicate the location of a computer or other device on a network.
IP address classes
IPv4 IP address, there are five classes of available IP ranges:
Class A
Class B
Class C
Class D
Class E
Only A, B, C are commonly used.
Each class has its range of valid IP addresses are shown below :
| Class | Address Range | Supports |
| Class A | 1.0.0.1 to 126.255.255.254 | Supports 16 million hosts on each of 127 networks. |
| Class B | 128.1.0.1 to 191.255.255.254 | Supports 65,000 hosts on each of 16,000 networks. |
| Class C | 192.0.1.1 to 223.255.254.254 | Supports 254 hosts on each of 2 million networks. |
| Class D | 224.0.0.0 to 239.255.255.255 | Reserved for multicast groups. |
| Class E | 240.0.0.0 to 254.255.255.254 | Reserved for future use, or Research and Development Purposes. |
Range from 127.0.0.0 are reserved for the loopback or localhost i.e. 127.0.0.1