We start from the viewpoint of quantum canonical transformations, analogues of the usual classical canonical transformations. We show that in the quantum case, such transformations lead naturally to the definition of some important quantum optics states, including the vacuum, coherent states, squeezed vacuum and squeezed states. We then go on to considerquons, operators satisfying deformed versions of the canonical commutation relations. Extending the idea of a canonical transformation todeformedquantum commutators gives quon analogues of these states, quon states. We finally show that this approach provides us with defining relations for some quantum groups. ©2000 American Institute of Physics.