Are gunite and plaster the same thing?

No! A gunite pool indicates the underlying STRUCTURE. Plaster is the final FINISH on top of the gunite structure. All inground gunite pools have the same structure (gunite or dry shotcrete – synonymous terms). The final stage of construction entails applying an interior finish, such as plaster. Plaster is also called marcite or merbelite. It is one of many types of interior finishes available for a gunite pool. Just like one can have a painted house, vinyl siding or clapboard, one can have a custom gunite inground pool with different interior finish options.