Unitary representations of groups duals and characters Unitary dual and primitive dual Representations of locally compact abelian groups Examples of irreducible representations Finite dimensional irreducible representations Describing all irreducible representations of some semi direct products Types for representations quasi duals groups of type I Non type I groups Representations of C* algebras and of LC groups the Glimm theorem Examples of primitive duals Normal quasi dual and characters Finite characters and Thomas dual Examples of Thomas duals The group measure space construction Construction of factor representations for some semi direct products Separating families of finite type representations.