IPv4 stands for Internet Protocol version 4, which is the fourth version of the Internet Protocol (IP) . It is one of the core protocols of standards-based internetworking methods in the Internet and other packet-switched networks. IPv4 was first deployed for production on SATNET in 1982 and on the ARPANET in January 1983. It is still used to route most Internet traffic today, even with the ongoing deployment of Internet Protocol version 6 (IPv6), its successor.
IPv4 uses a 32-bit address space which provides 4,294,967,296 (2^32) unique addresses. However, large blocks are reserved for special networking purposes. IPv4 addresses are expressed in dot-decimal notation, which is a series of four eight-bit binary numbers separated by a decimal point. Although any numbering system can be used to represent a unique 32-bit number, most commonly IP addresses are expressed in dot-decimal notation.
IPv4 is a connectionless protocol and operates on a best-effort delivery model. It does not need to guarantee delivery, which makes it a fast protocol. IPv4 establishes the rules and limitations for communication over the Internet or on a local network. It is still a popular protocol for communication over the Internet and other packet-switched networks.
