Welcome, and thank you for your interest 
Although the term "Hypnosis" was derived from the Greek word hypnos, meaning sleep, Hypnosis is not sleep, but a natural, normal, relaxed and focused state of attention or "trance state" that is characterised by:
It is important to remember that hypnosis per se is not "therapy" : the skilled practice of clinical hypnotherapy resides in the way in which hypnosis is used to optimise a broad range of psychotherapy and counselling techniques to facilitate whatever healing and change is appropriate for you in your particular situation.
Contrary to some of the myths surrounding Hypnosis, you cannot be made to do anything you do not want to do nor will you "reveal your deepest secrets" either - it is even possible to tell lies while under hypnosis. You can only be guided into the hypnotic state by your therapist if you want to be and all hypnosis is in fact self hypnosis.