There’s probably less than you think, especially between a counsellor and a psychotherapist. All three can use various techniques but some specialise, for example in Cognitive Behaviour Therapy, whilst others use several techniques because some may lend themselves better to you and your situation.
Psychotherapists and counsellors may specialise in working with individuals, small groups, couples, adults or children. They may have particular interests (in post-traumatic stress disorder – PTSD – for example, or couples therapy) and their training and experience will reflect that. Whether somebody calls themselves a psychotherapist or a counsellor can be down simply to the way they see their work; counselling tends to bring to mind a more conversational and apparently less structured and informal exchange (despite often using structured techniques) and that may sum up the therapist’s view of how they work. A psychotherapist may see themselves as having a more structured approach, and having a more formal relationship with their clients. Both psychotherapists and counsellors will have professional qualifications and experience and belong to a professional body that regulates their practice. We check that but it’s important that you do too.
Psychologists’ titles, such as clinical psychologist, or educational psychologist, are protected in law (unlike a counsellor or psychotherapist) and will be registered with the Health and Care Professions Council so people using those titles are guaranteed to have completed the proper training and are regulated by the HCPC. Psychologists use psychological research and theory in their therapeutic work (often counsellors and psychotherapists do too) but will almost certainly have a greater expertise and depth of psychological understanding underpinning the way they practise. They often treat the same psychological problems as psychotherapists and counsellors but may also be involved in more complex cases where clinical knowledge enables them to diagnose and work with other medical professionals.