Coaxial cable can be used for the transmission of analog and digital signals.
Coaxial cable is a kind of wire and signal transmission line, which is generally made of four layers of materials: the innermost is a conductive copper wire, the outer surface of the wire is surrounded by a layer of plastic (used as an insulator and a dielectric), and the outer surface of the insulator is surrounded by a layer of plastic. There is a thin layer of mesh conductor (usually copper or alloy), and then the outermost layer of the conductor is the outermost insulating material as the outer skin.
