The biggest difference is to families that have some sort of health coverage plan. Some plans cover one of those two practitioners, some plans cover both. Each plan has been negotiated by the entity providing the plan (usually your employer). There are a number of professionals registered with colleges in Ontario that are permitted to practise within the controlled act of psychotherapy. Registered Social Workers and Registered Psychotherapists are the two most common practitioners that offer psychotherapy. The only significant difference between the two is that you will also find Registered Social Workers employed in a variety of capacities and places whereas Registered Psychotherapists tend to only be employed in a psychotherapy setting.