What do you think when you hear that word?
I'm guessing most people would think of mind control, body control, no control in fact, and possibly relaxation. Maybe a way of telling you things that you didn't know about yourself.
But what is is really?
Well, the only part in the above description that was one hundred percent correct was a way of relaxing you. And the part about knowing yourself better.
The word Hypnosis derives from the Greek word Hypnos, who was the Greek god/personification of sleep.
Hypnotherapy was founded by Sigmund Freud, when he founded his psychoanalytical approach to psychology. (I know, he was a little crazy with the whole fancying your mother thing and dreaming about phallic symbols, but some good did come out of it. Like hypnotherapy and dream dictionaries. -come on, they are quite funny.)
I myself am undergoing hypnotherapy at my university and being honest, I think it may have helped. Only slightly, but then again, I haven't had many sessions.
But from my experience hypnotism takes you away to a place where only you can go to. It's the most wonderful, peaceful place you can think or dream of. And it's all yours. Mine, for example is a wood-surrounded garden filled with flowers, birds and butterflies. A sparkling river runs through it and the sun beats down. The gentle zephyrs carry only the fragrance of flowers, wood and late spring.
It's always nice to go to that place and just sit in the garden and think.
I think Derren Brown is probably a good name to drop here.
A common misconception is also that when you are 'under', it's difficult to get out. From my own experience I've found that this isn't the case. You are always aware of your surroundings, so much so it's sometimes hard to get into the right state, as even small noises can be a distraction.
Although I could tell you much about my own experiences, it's probably better left to the experts.
So, if you'd like more information I would recommend the following links:
The Hypnotherapy Association UK
Wikipedia's Extensive page on Hypnotherapy
(please note that Wikipedia pages may not be 100% correct)