Also known as talking therapies, the terms psychotherapy, counselling and therapy cause a lot of confusion. Below are the definitions according to the Cambridge Dictionary (Source: https://dictionary.cambridge.org/):
Therapy is the job or process of listening to someone and giving that person advice about their problems and how to deal with them
Psychotherapy is the treatment of mental illness by discussing someone's problems with them, instead of using drugs or operations
Therapy is a treatment that helps someone feel better, grow stronger, etc., especially after an illness: illness disease or injury
Practically, therapists use the terms interchangeably or only one title depending on the training they have received. The biggest difference maybe each professional approaches the problem and what skills they have to help you. Professionals with a medical background can give advice. Those without should not but may offer suggestions.
Here’s a tip: Look at a professional’s qualifications, ask questions in relation to your problem and find out how you might work together. If it doesn’t work for you, you can stop.