You must look at the root system to distinguish between the two. Turf has a bunch-type growth and will feel thicker when you walk on it. Empire Zoysia, Palisades Zoysia, Cavalier Zoysia, and Jamur Zoysia are examples of turf.
Grass spreads by developing rhizomes under the ground and will feel thinner. Bermuda grass and Centipede grass are two examples.
Both turf and grass are excellent choices but your selection depends on the location in which you are going to plant the grass or turf, drought conditions, the maintenance involved, and the grass or turf’s tolerance to heat and cold conditions.