How does coax cable work?
A coaxial cable is the same as any other wire other than the fact that it has a center conductor and the other wire lead is wrapped around the center conductor, which is usually separated by a foam core. Without getting into the specifics on dialectric constants, frequency responses and loss in .db/100 feet in length, what it essentially does is use the ground lead as a shield to prevent interference from getting into the center conductor. This makes it ideal for carrying different types of signals that need to be `clean' when it arrives at the termination point.
Hope this helps,