Computer Science – 2.1 Networks including the internet | e-Consult

A Network Interface Card (NIC) is a hardware component that allows a computer to connect to a LAN. Its primary function is to provide the physical interface between the computer and the network cable or wireless signal.

Addressing: The NIC contains a unique Media Access Control (MAC) address, which is a physical address assigned to the card by the manufacturer. This MAC address is used to identify the device on the network. When a device sends data, it includes the destination MAC address to ensure the data reaches the correct recipient. The NIC uses this address for both sending and receiving data.

Data Transmission: The NIC is responsible for converting data from the computer's format into a format suitable for transmission over the network medium (e.g., electrical signals over a cable, radio waves for Wi-Fi). It handles the physical layer aspects of data transmission, including encoding, modulation, and signal generation. It also receives data from the network medium, decodes it, and passes it to the operating system. The NIC manages the flow of data to and from the network, including handling collisions (in older Ethernet networks) and ensuring reliable data delivery. It also interacts with the network operating system to manage network protocols.