Which layer directly interfaces with network cables?

The layer that directly interfaces with network cables is the Physical Layer. This layer is responsible for the actual transmission of raw bitstreams over a physical medium. It deals with the hardware aspects of networking, including the electrical signals, optical signals, or radio waves that traverse the physical network infrastructure such as cables, network interface cards, and connectors.

The Physical Layer defines the characteristics of the physical medium and the ways in which data is transmitted over it. This includes specifications for cables, signaling, and the physical aspects of the network architecture. It ensures that data can be effectively sent and received across different devices connected within the network. Thus, the connection to network cables occurs at this level, as it is fundamentally concerned with the physical transmission of data, rather than the content or structure of the data itself.