What type of data representation is defined at Layer 3 of the OSI 7-Layer Model?

Layer 3 of the OSI 7-Layer Model is responsible for the Network layer, which primarily handles routing and forwarding of data packets across different networks. The key concept associated with this layer is the "packet," which is the data representation used to encapsulate and send information between devices over a network.

Packets include both the payload (the actual data being sent) and control information, which helps in determining the packet's route through the network, including addressing and error-checking information. This distinction is crucial because it enables various devices on different networks to communicate effectively, facilitating the process of routing data from the source to the destination based on IP addressing.

The other options represent lower layers in the OSI model, where "frame" is related to the Data Link layer (Layer 2), typically used for data transferred over a single network segment. "Byte" and "bit" represent even lower levels of data representation, with a byte being a unit of digital information that consists of eight bits and neither are specifically related to Layer 3 encapsulation. This clearer understanding of how data is encapsulated at the Network layer underlines the importance of the packet in the communication model.