Description: This document is a definition document intended to help grow understanding of the OSI model, specifically the Physical Layer of the model.

The Physical layer makes up the form of connection between two devices. For example while using a copper-wire network such as Ethernet, the wires and the electromagnetic signals traveling through the wires would make up the physical layer. When using wireless, the physical antenna and electromagnetic waves in the air make up the physical layer.

Think of the Physical layer like the rail road tracks for a train. A train uses the train tracks to move around cargo, just as a network uses the physical layer (wired signal, wireless signal) to move around information.

Be sure to check the next document the Data Link Layer!