Generalized symmetric riemannian spaces -- Reductive spaces -- Differentiable s-manifolds -- Locally regular s-manifolds -- Operations with s-manifolds -- Distinguished s-structures on generalized symmetric spaces -- The classification of generalized symmetric Riemannian spaces in low dimensions -- The classification of generalized affine symmetric spaces in low dimensions -- Existence of generalized symmetric spaces of solvable type -- Irreducible generalized affine symmetric spaces -- Generalized pointwise symmetric spaces -- Non-parallel s-structures on symmetric spaces -- Some advanced results