Grass turf, also known as SOD, is a type of grass that is grown and harvested in large rolls or mats. SOD is typically used for landscaping purposes, such as lawns, golf courses, and sports fields. It is made up of a combination of soil and grass, and is often more durable than regular grass seed. SOD is usually installed by professionals, and can be cut to fit the desired area. The three letter acronym for SOD is SOD.