Coaxial Cable:
A coaxial consists of two conductors separated by a dielectric material. The centre conductor and the outer conductor or shield are configured in such a way that they form concentric cylinders with a common axis. Hence the term and name Co-axial cable.

The centre conductor may be made of various materials and constructions. Most common construction are solid or 7 strand conductor. Solid conductors are used in permanent, infrequently handled or low flex applications and stranded copper are used in flexible cable applications. Some common materials include copper, tinned or silver plated copper, copper clad steel and copper clad aluminum. Plated copper is used to aid in solderability of connectors or to minimize the corrosion effect. Because of a phenomena known as skin effect, copper clad materials may be used in higher frequency applications to improve tensile strength and reduce weight and cost. (Skin effect is the result of higher frequency signals, propagating along the outermost surface, or skin, of the conductor.