network interface controller is a computer hardware referred to as a network adapter.

1. A network interface controller is a computer hardware component that connects a computer to a computer network. The controller may also be referred to as a network adapter, or a LAN adapter
2. The NIC allows computers to communicate over a computer network. It is both an OSI layer 1 (physical layer) and layer 2 (data link layer) device
3. Every Ethernet network card has a unique 48-bit serial number called a MAC address, which is stored in ROM carried on the card.
4. 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
5. A network card typically has a RJ45, 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
6. The 'controller' may take the form of a network card that is installed inside a computer, or it may refer to an embedded component as part of a computer motherboard, a router, expansion card, printer interface or a USB device.
7. network cards used to be expansion cards that plug into a computer bus, the low cost and ubiquity of the Ethernet standard means that most newer computers have a network interface built into the motherboard.
8. It allows users to connect to each other either by using cables or wirelessly.
9. Programmed I/O is where the microprocessor alerts the designated peripheral by applying its address to the system's address bus.
10. Network cards are typically available in 10/100/1000 Mbit/s varieties. This means they can support a notional maximum transfer rate of 10, 100 or 1000 Megabits per second.