Carpet tiles are sections of broadloom carpet cut into squares or rectangles that are backed with a rigid vinyl (or equivalent) type of backing. They are primarily used in the commercial world, as they have one dominate advantage of being able to be replaced quite easily by anybody. You can do many different patterns with the tiles as well. When an area is soiled, stained or damaged the tiles can be easily peeled off and replaced with new tiles. No cutting or gluing is needed. The replacement piece falls right into place. They are not cheaper due to this convenience and the extra manufacturing to process them into tile. We have not seen many in the residential world yet, but they may be on the horizon due to the popularity in the commercial world.