Given a complex algebraic variety one can associate to it a variety of interesting cohomological invariants. For example the "classical" topological invariants such as singular cohomology or complex K-theory or more geometric invariants such as motivic cohomology or algebraic K-theory. In between there are also invariants such as morphic cohomology defined by Friedlander-Lawson and semi-topological K-theory defined by Friedlander-Walker. In this talk we will discuss these invariants and some interesting relations between them.