It's a set of tools. Hypnosis is a set of procedures that can be used to alter someone's state of consciousness and direct them, or yourself in a way which is useful for attaining a particular outcome. In fact, most people can be talked into doing absurd things simply by talking with them. It is less likely that a person in trance would do anything that wouldn't positively benefit them in some way. Hypnosis is a way to bypass conscious resistance and begin to amplify inner resources, or to develop new resources that enable a person to feel better about themselves, develop a positive mental attitude, or make the changes they desire.
Any effective communication is hypnosis.
Successful poets, attorneys, salespeople, parents, politicians, religious leaders, etc. The same language is often inadvertently used to get unwanted responses. The listener has to think about doing the behavior in order to understand what has been said, and this makes the behavior more likely to occur. Most books present hypnosis as something that you sit down and do on yourself or on someone else for a specific period of time, usually to solve problems. Then you get up and do something else.