Hypnosis is a mental state which can be induced by a procedure called hypnotic induction, utilizing a series of preliminary instructions. There are many applications for hypnosis - it can be used as a form of therapy (hypnotherapy) to curb unwanted habits or behaviors such as smoking or other addictions. It is also used as a form of entertainment during which a hypnotist puts members of the audience to sleep and puts on a show using them to enact entertaining scenarios. There are also many different hypnosis techniques which can be used to influence the unconscious mind of an individual for a variety of purposes. Erotic hypnosis is sometimes used by individuals to reduce their inhibitions and to increase arousal. Most frequently used within a dominance and submission-type relationship, erotic hypnosis can be a form of erotic power exchange.

Hypnotherapy is one of the most widely-used hypnosis techniques, used for many medical applications such pain management, weight loss, soothing anxiety, habit control, and sports performance. While hypnotherapy is most often overseen by an expert, there are several methods of self-hypnosis which people often use to quit smoking. Hypnosis techniques can be utilized online or through video or audio recordings within the comfort of one's own home. Other medical applications of hypnosis include studies involving the use of hypnosis to treat irritable bowel syndrome and to decrease pain in childbirth, also referred to as hypnobirthing.

Another popular form of hypnosis is stage hypnosis, used as a form of entertainment usually performed in front of a live audience. There are three strategies used during stage hypnosis: participant compliance, participant selection, and deception of the audience. Participant compliance is generally fairly easy to achieve due to factors such as peer pressure and the participant's desire to be the center of attention. Participant selection involves a series of preliminary suggestion tests which the performer uses to pick out the most suggestible members of the audience. Tests might include things like asking the audience to clasp their hands together, then suggesting that they cannot be separated. The deception of the audience is a critical part of stage hypnosis and there are many different strategies which may be utilized. Off-microphone whispers may be used to whisper instructions to the participants outside the audience's hearing or sleight of hand tricks.

Hypnosis is used in a variety of different forms for both medical and entertainment-based reasons. While there is a great deal of debate surrounding the "science" of hypnosis, there is a large population of scientists and psychologists who place enough faith in the concept to use hypnosis on their patients.