Latex literally means "polymers suspended in water" and can be 100% natural, 100% synthetic or a blend of the two. It is manufactured via one of two processes: the Dunlop process or the Talalay process.
Viscoelastic Foam (Memory Foam):
Viscoelastic foam is a type of polyurethane foam and is therefore synthetic. Its name is derived from the word "visco," which means "resistant to change of shape" and "elastic," which means "the ability of something to return to its original shape after being forced to change." Viscoelastic foam, which is commonly known today as memory foam, was originally developed in the late 1960s by NASA. The result was a very dense, open cell variety of polyurethane foam that molded to the weight and shape and temperature of an individual. Unlike latex or standard polyurethane foam, it is a slow-response foam and gradually conforms to your body and temperature. It also takes a certain amount of time to recover and resume its original shape. Due to its high density, it helps to reduce pressure points as well as minimize motion transfer. However, it is not as breathable as other mattresses and has a tendency to become hot while you sleep.