IPv4 is a version of the IP(Internet Protocol) that is fundamental for the operation of the Internet. It is the primal Internet protocol responsible for transmitting data packages and locating hosts. There are two IP versions that are used today: IPv4 and IPv6. IPv4 is the predominant version of the Internet Protocol at the present. Some of the IPv4 addresses are reserved by IANA for special purposes including private networks or multicast.
The IP enables communication between devices in a network. That’s why every device connected to a network using the IP protocol is given a unique numeric identifier that defines where it is on the Internet – that is its IP address. Personal computers and other devices usually have dynamic IP address generated by a DHCP server on the network they are currently using and could be easily changed. However, servers have static IP addresses in order to be always quickly accessed at the same address.
IPv4 addresses have 32 bits (or 4 bytes) expressed with the decimal numeral system for convenience. They consist of the 8 bits/1 octets represented as decimal numbers (four numbers ranging from 0 to 255), separated by periods. This limits the possible IPv4 addresses to about 4.3 billion. Now almost all of these addresses are assigned and for that reason, the IPv6 has been developed and it supports 128-bit addresses. In 2011 the last 8 address blocks were assigned and some companies started switching from IPv4 to the new protocol.