A W-algebra is introduced as a symmetry algebra in 2-dimensional conformal field theory. Mathematical realization of a W-algebra was introduced by the theory of vertex algebras. Especially, W-algebras related to Lie superalgebras have been studied by many mathematicians and physicists. Moreover, classical W-algebras (classification of W-algebras) and finite W-algebras (finitization of W-algebras) are interesting objects in integrable systems theory and representation theories. In this talk, I will briefly introduce (classical, finite) W-algebras associated Lie superalgebras and related topics.