Which layer of the OSI model deals with the physical connection between devices?

The Physical layer is the correct choice because it is the lowest layer of the OSI model, responsible for the actual physical connection and transmission of raw bit streams over a physical medium. This includes the hardware technologies involved, such as cables, switches, and network interfaces, and defines the electrical signals, timing, and physical layout of connectors and devices that enable communication between them.

This layer ensures that when data is sent from one device, it can be received by another device across whatever physical medium connects them, whether that be copper wires, fiber optics, or even wireless connections. It sets the foundation for all higher layers of the OSI model, as they rely on the reliable transfer of bits provided by the Physical layer. Understanding this layer's function is crucial for troubleshooting connectivity issues and implementing networks effectively.