What is the Physical Layer Protocol, and what is the interface? What is the difference and is it?
In one of the sources read> Physical interface is determined by a set of electrical connections and characteristics of signals. The interface sets the parameters, procedures and characteristics of the interaction of objects.
Other source> The physical protocol is determined by the characteristics of the communication channels, signals and port connectors.
Those. When communicating computer to computer, the communication channel and the characteristics of the transmitted signals is a protocol, an interface or all together?
Explain, please. thank