Short for Network Interface Card, the NIC is also referred to as an Ethernet card and network adapter. It is an expansion card that enables a computer to connect to a network; such as a home network, or the Internet using an Ethernet cable with an RJ-45 connector.
Due to the popularity and low cost of the Ethernet standard, most new computers have a network interface build directly into the motherboard. The top image shows the SMC EZ Card 10/100 PCI network card, one of the more common examples.
How does a computer with a network card connect to a network?
A network card can communicate with each other over the same network using a network switch or if only two computers a direct connection. If computers on your network need to connect to a different network (e.g. the Internet) they must be eventually connected to a router that allows networks to communicate with each other.