HI...
A counsellor is a person who is involved in counselling. It refers to a person who is concerned with the profession of giving advice on various things such as academic matters, vocational issues and personal relationships. He is a generally a professional and an expert in his field of functioning. There are different types of counsellors such as rehabilitation counsellor, Marriage and Family counsellor, School counsellor, Mental Health counsellor, online counsellor and Legal counsellor.
A consultant, is a person who provides expert advice professionally.