Stalks of coherent sheaves on quasi-projective varieties

Like many concepts in geometry, one would like to be able to work locally in a neighbourhood of a point. In this video, we show that one can study coherent sheaves from this local viewpoint using the notion of a stalk. We introduce the basic concept as well as some simple properties which show for example how we can check morphism of coherent sheaves are injective or bijective by just looking at stalks. We also show how the notion of stalks allows us to associate to any coherent sheaf a closed subset of the variety called its support. This gives us some way to visualise coherent sheaves.