Trex is a brand name not a style of decking. Trex has claimed to be the first company to produce composite decking, which probably explains why many people refer to all composite decking as Trex decking.
Composite Decking is a type of deck material, used as an alternative to wood or plastic decking. Composite is a mixture of wood and plastic and allows for a maintenance free product.
Comparing the top 3 types of decking