The term active learning, first introduced by English scholar R W Revans, is a learning process in which students physically participate in the learning process, rather than through merely listening to information (which is passive learning).
For instance, when students study science they can listen to lectures, or they can go into a lab and physically conduct experiments. By conducting experiments a student becomes physically involved in the processes of science (actions and reactions) and this is ultimately more memorable than listening and taking notes.