At which layer of the OSI Model is data represented as frames?

Data is represented as frames at the Data Link layer, which is the second layer of the OSI Model. This layer is responsible for establishing, maintaining, and deciding how transfer is accomplished over the physical layer.

Frames are a critical component of this layer because they serve to encapsulate network layer packets and add essential control information such as source and destination MAC addresses, error-checking data, and the sequence of the frames. These elements ensure that the data can be reliably transmitted across the physical medium and that any potential errors in transmission are detected and handled.

By functioning at this level, the Data Link layer manages the way data frames are sent over a physical medium, allowing for efficient error detection and correction, and making sure the data packets are properly formatted and addressed for delivery. This emphasis on framing distinguishes the Data Link layer from other layers, which handle different aspects of network communication, such as packet routing at the Network layer or end-to-end communication at the Transport layer.