What is a communication channel ? Name the basic types of communication channels available.

A communication channel is a means of communication between two devices or workstations i.e., it refers to the medium used to carry information or data from one point to another. Communication channels can be grouped in two categories:

1. Guided media — These media include cables. There are three basic types of cables :
   1. Twisted-Pair Cables
   2. Coaxial Cables
   3. Fiber-optic Cables
2. Unguided media — These include waves through air, water or vacuum. Unsigned communication media are as follows:
   1. Microwaves
   2. Radiowaves
   3. Satellites