By making you conscious of any tension within you, meditation can sometimes lead to a state of relaxation, but such relaxation should not be the aim. Reread our definition of meditation to understand the principles and aims of the practice. Some of the early meditation exercises, particularly those involving breathing, may remind you of relaxation or sophrology exercises, but they will not encourage or push you to relax.
Don't waste too much time on such theoretical considerations. Only meditation practice will teach you what it's about.