This is a part of the research seminar on intertwining operators.
Many interesting categories, such as the category of representations of GL_n quantum group are ribbon tensor categories, which basically means that morphisms can be encoded by ribbon diagrams, as introduced by Reshetikhin and Turaev. I will explain what this means and how to describe GL_n, affine GL_n and toroidal GL_n quantum groups in this formalizm. This serves as a bridge between representation theory and 3-dimensional topology. Also the generalization of the Schur-Weil duality to duality between quantum groups and Hecke algebras appears naturally. I hope this talk will serve as basis for the subsequent talks about quantum groups.