CMP cables are plenum cables; these cables are used if networking must be done in air ducts. They can be used for commercial or residential spaces. They will not combust and cannot actually cause fires. If the cable is in the path of a fire, it melts and emits very little toxic fumes.

CMR cables are riser cables. These are used for regular networking from room to room, as long as the cable does not need to pass through an air duct. For example, if you drill a small hole in the living room floor, you can run a CMR cable into the basement.

CM/CMG are the most commonly used commercial grade communication cable.

CMX is a residential grade cable. Such cables are limited to residential or other small applications where the number of communication cables used is very little.