Which layer of the OSI model is associated with the Network Interface Card?

The Network Interface Card (NIC) operates primarily at Layer 1, which is the Physical Layer of the OSI model. This layer is responsible for the transmission and reception of raw data bits over a physical medium. The NIC serves as the hardware interface between a computer or other device and the network, handling the conversion of digital data into electrical signals (or other forms, like optical signals), which can be transmitted over a medium such as cables or wireless transmissions.

At Layer 1, the focus is on the physical aspects of network communication, including connectors, network cables, radio frequencies, and modulation techniques. The NIC facilitates the basic transmission of data and ensures that signals are properly sent and received, serving as the foundation for networking.

Layer 2, which is the Data Link Layer, does play a role in the operation of a NIC through its functions related to addressing and framing. However, the primary association of the NIC is with Layer 1, since it is fundamentally about the interface with the physical network infrastructure. Layers 3 (the Network Layer), which deals with logical addressing and routing, and Layer 4 (the Transport Layer), which manages end-to-end communication and data transport, are not directly associated with the functions of a Network Interface Card