Coaxial cable is most widely used for T.V. applications, e.g., connecting V.C.R to TV or satellite etc. or nowadays modem to computer. It is usually an insulated steel core with a copper flashing surrounded with a copper or aluminium braid with an extra layer of insulation. Coax is considered the lowest grade of wire. Video coax on the other hand has a copper core with a copper braid and is much better than regular coax.