A transitional network card with both BNC "Thinnet" (left) and Twisted pair (right) connectors.

A network card (also called network adapter, network interface card, NIC, etc.) is a piece of computer hardware designed to provide for computer communication over a computer network.

The card implements the electronic circuitry required to communicate using a specific physical layer and data link layer standard such as ethernet or token ring. This provides a base for a full network protocol stack, allowing communication among small groups of computers on the same LAN and large-scale network communications through routable protocols, such as IP.

A network card typically has a twisted pair, BNC, or AUI socket where the network cable is connected, and a few LEDs to inform the user of whether the network is active, and whether or not there is data being transmitted on it.

Most newer computers have a network interface built into the motherboard, so a separate network card is not required unless multiple interfaces are needed or some other type of network is used.

Notable manufacturers

• 3Com Corporation
• Intel
• Novell

See also

• MAC address
• TCP Offload Engine (TOE)
• Host Bus Adapter (HBA)
• Wireless network interface card (WNIC)