The physical layer is the lowest layer (Layer 1) of the OSI (Open Systems Interconnection) reference model, responsible for the actual transmission of raw data bits over a physical medium such as copper wire, fiber …

The physical layer is the lowest layer (Layer 1) of the OSI (Open Systems Interconnection) reference model, responsible for the actual transmission of raw data bits over a physical medium such as copper wire, fiber optics, or wireless radio signals.