The role of the network interface card is to act as a translator for data being sent and received via a network. The computer peripheral handles changing data back and forth between a format of bytes that the computer can work with and a format that can be transmitted along cables.
Network interface cards come equipped to handle different, or multiple, types of networks. Serial cables, Token Ring, Ethernet and Wi-Fi are all forms of networks that interface cards are designed to communicate on. Most modern networks are composed heavily of Ethernet and Wi-Fi connections. The network interface card provides the hardware for multiple network layers to exist on, meaning it is able to handle having multiple addresses depending on the network it communicates across. This allows a computer to sync or transfer data along a local office server using one, while still being able to communicate across the Internet with another. Network interface cards also provide a buffer for incoming and outgoing data, so that the computer can compensate for latency issues. Many modern devices have network interface cards built into them, as standards have made Ethernet and IEEE 802.11 (used for wireless local access network connections) widespread and compact.