Kool Deck is a trade name for a deck surface that is somewhat porous, no very durable and but stays cooler than most other deck surfaces. Acrylic deck coating looks a lot like Kool Deck, but it's non porous, much more durable. The process begins with a texture coat that can be sprayed on or troweled the simulate almost any surface, from flagstone to brick to whatever you desire. The texture is then followed with an acrylic colored top coat.
I have had an acrylic coated deck for 12 years. After 5 years or so it was looking a bit tired and there were a few chips here and there. A five gallon pail of top coat (about $100) and one afternoon with a paint roller made it like new. It is important if you have acrylic to keep some top coat around and touch up any chips as soon as they appear. Water can get under the surface and cause it to peel if they are left untreated. With a bit of TLC an acrylic deck is very durable and can be kept looking just like new indefinitely.