Networks are able to function when computers, printers, and other devices are able to send data to each other, either through cables or wireless signals. This transfer of data is made possible by sets of data transmission rules called protocols. A protocol can be thought of as a language that has rules so that participants can effectively communicate with each other.
Different types of networks use different protocols, but Transmission Control Protocol/Internet Protocol (TCP/IP) is the most popular. TCP/IP is used to send data over the Internet as well as over most corporate and home networks.
Every device on a network that uses TCP/IP must have an IP address. IP addresses are essentially unique computer names in a numeric format, used to transfer data around a network. IP addresses allow TCP/IP to confirm requests for, and receipt of, data by various devices on the network.