In this article, an overview of the background, the research approaches and the patterns of practice in the field of collaborative learning are provided. A definition of collaborative learning and an overview of fundamental aspects that shape research and practice in this field are included. Pedagogies and learning theories that are used as foundations of the field alongside goals and objectives of collaborative learning approaches are discussed. Popular patterns of practice, exploring their application in classrooms and elaborating on the state of the art around those practices in research are outlined. A discussion about important topics, open questions and future directions are provided in conclusion.