To be hypnotized is to allow yourself to be in an extremely relaxed state. Depending on your issue, the idea is to address emotional states and beliefs that prevent you from living the life you want. For example if you have a fear of flying, hypnosis is one of, if not the only, way to eliminate that fear, it can change addictive behaviours or if you lack confidence, hypnotic suggestions can quickly help you gain what you need. It is not a form of mind control, but more an agreement between you and your hypnotherapist to achieve a goal.
The difference between an Hypnotherapist and a person who is not qualified is similar to calling a hill a mountain. Understanding the complex relationship between the mind and language is a learned skill, meditation leaves you free to explore abstract ideas or have a personal experience, there are good and bad meditations, but in the main they are not delving into your mind to the same degree hypnosis does.
In complicated situations you may need a number of sessions to get where you want to be, your hypnotherapist will ‘induce’ a state of deep relaxation (trance) which frees your mind to create a new scenario as the mind is essentially a sponge ruled by a belief. Panic attacks show us that belief can override reality in any one moment, if the belief is strong enough, Hypnosis seeks to override the belief in favour of reality. If you think of your mind as having two conscious states that work simultaneously, your rational mind, and your instinctive mind.
The instinctive mind is the one that through repeated practice or teaching works faster than your rational mind, when they are at odds, you will have one part of your mind screaming at the other, for example, you go to the fridge and grab something to eat, all the while you are consciously telling yourself you don’t need that, you are not hungry, but you do it anyway. The instinctively mind will win any day of the week as it is intrinsically connected to your body so by relaxing (essentially boring) the rational mind, hypnotherapy forms a direct connection to that instinctive mind creating a new foundation for behaviours.