Ergodic Theory is a powerful tool in the study of linear groups. When trying to crystallize its role, emerges the theory of AREAs, that is Algebraic Representations of Ergodic Actions, which provides a categorical framework for various previously studied concepts and methods. Roughly, this theory extends the focus of Representation Theory from Groups to Group Actions, exploiting the tension between Ergodic Theory and Algebraic Geometry. In this series of talks I will introduce this theory and survey some of its applications, focusing on Superrigidity and Arithmeticity results.