What is Hypnosis? The Process

One of the most frustrating and confusing things one can come across when learning something new is having the inability to properly define it, or worse, having many confusing and conflicting ideas and definitions thrown at you! Hypnosis is one of those things that has gotten this shadow of confusion cast upon it, hopefully I can alleviate this for you now. Hypnosis has been described as being an "altered state of consciousness", I would like to say that that is incorrect, as it is altered from what exactly?