Hypnosis comes from the Greek word 'hypnos' meaning sleep. It is often confused and has been given bad publicity by science fiction and other media that depict it as a way of getting a person to do anything you want without their permission.
In reality hypnosis is placing a person into a kind of trance like state, simply a psychological condition where they are more open to suggestion and supposedly their subconscious comes to the fore. What is actually going on is widely argued by scientists and therapists. It is used for a variety of things from entertainment to part of a therapeutic healing program.
Stage hypnotists put members of the audience into a relaxed state using a variety of techniques but usually verbal soothing. The person appears to be in a trance and can now be made to perform speech or actions. It is debated how much of this is actually hypnosis and how much is suggestibility. Some say that hypnosis is no different to the way in which people can be made to do things through suggestion and subtle manipulation. Many believe that it is impossible to make someone do something that is actually against their will. In any case it takes a brave or foolish person to allow a hypnotist to take control of their mind!
In therapy, hypnosis is used to relax a patient and allow them to talk more freely about themselves. It is used to regress a patient, which takes them back mentally to a previous time and allows them to speak about things they normally bury under other memories or day to day concerns. In any case many therapists say that hypnosis or similar relaxation techniques can drastically help a patient.
It is even possible to hypnotise yourself, a process called autosuggestion. There are a variety of techniques and they allow a person to program themselves to improve their diet, stop habits, etc. It again is debatable whether this is truly hypnosis or simply good training or even a simple placebo effect.
