A network card, also known as a network interface card (NIC) or network adapter, is a hardware component that allows a computer or other electronic device to connect to a network. It enables the device to communicate with other devices and access resources over a local area network (LAN) or a wide area network (WAN), such as the internet.

The network card serves as an interface between the computer's internal data processing components and the external network transmission media, such as Ethernet cables or Wi-Fi signals. It converts digital data produced by the computer into electrical signals (for wired connections) or radio waves (for wireless connections) to be transmitted over the network.

Network cards can be either integrated into the motherboard of a computer (onboard NIC) or added as an expansion card into a specific slot on the motherboard (addon NIC). Most modern computers come with onboard network interfaces that support Ethernet connections, while wireless network adapters are often provided as separate addon cards or as integrated components.

Whether wired or wireless, a network card is a crucial component that facilitates communication between computers and other networked devices, allowing users to access shared resources, share files, connect to the internet, and communicate with other users on the same network.