The philosophical position that free will exists and determinism is true. Soft determinism implies compatibilism because one must believe that free will and determinism are compatible if one believes they both are true. Also, almost all compatibilists are soft determinists as well.
There are two common philosophical positions regarding free will and determinism that contrast with soft determinism. Hard determinism says that determinism is true, but free will does not exist. Libertarianism says that free will exists, and determinism is false. These are both known as incompatibilist positions.