An IP address is a unique numerical identifier that is assigned to each device connected to a computer network that uses the Internet Protocol for communication. It serves as a routing and identification address that identifies the network and host of a device on the internet.
IP addresses are divided into two versions: IPv4 and IPv6. IPv4 addresses are 32-bit numbers that are divided into four octets, each of which ranges from 0 to 255. IPv4 addresses are written in dotted-decimal notation, such as 192.168.1.1. IPv6 addresses are 128-bit numbers that are written in hexadecimal notation, such as
2001:0db8:85a3:0000:0000:8a2e:0370:7334.
IP addresses are further divided into classes, which are based on the size of the network and the number of hosts that can be connected to it. There are five classes of IP addresses: A, B, C, D, and E.
Class A IP addresses are used for large networks with a large number of hosts. The first bit of a Class A IP address is set to 0, and the next 7 bits represent the network identifier, which leaves 24 bits for the host identifier. This allows for up to 126 networks and over 16 million hosts per network.
Class B IP addresses are used for medium-sized networks. The first two bits of a Class B IP address are set to 10, and the next 14 bits represent the network identifier, which leaves 16 bits for the host identifier. This allows for up to 16,384 networks and 65,534 hosts per network.
Class C IP addresses are used for small networks. The first three bits of a Class C IP address are set to 110, and the next 21 bits represent the network identifier, which leaves 8 bits for the host identifier. This allows for up to 2 million networks and 254 hosts per network.
Class D IP addresses are used for multicast addresses, which are used to send messages to a group of devices on the network. The first four bits of a Class D IP address are set to 1110.
Class E IP addresses are reserved for experimental use and the first four bits of a Class E IP address are set to 1111.
In summary, IP addresses are unique numeric identifiers that identify devices on a computer network. They are classified into different classes based on the number of hosts and networks that can be connected to it, with Class A being the largest and Class E being reserved for experimental use.