The mind, in simple terms, is the conscious and subconscious mind. The conscious mind is the voice in our heads and the part of us that thinks, analyzes, and imagines, etc. and the subconscious is simply the nonjudgmental center of our being that receives the suggestions that our conscious mind delivers.
Understanding how this works allows us to take control more of the process of thinking and transformation because we can begin to see how the basic structure of mental transformation works. What we keep thinking about eventually sinks into the subconscious and creates grooves in that part of the brain making those thoughts eventually becoming a habit or frequency. The conscious mind is like the captain of the ship that is steering this spirit in a body and the subconscious mind is simply waiting for the orders you want to give it. The subconscious mind does not judge or discriminate, so if you keep sending negative messages, it is a guarantee that you will create a life of problems for yourself. If you want to really make powerful transformations, think of it in terms of how to make something sink deep into the subconscious, not just "positive thinking".
Do you see the difference between the two? For example, if you want to have more confidence as a speaker, it’s important to find a way to make the realization of that desire sink deep into the subconscious mind with empowering thoughts and images so that now you have made the feeling of confidence into a habit-pattern in your brain. Compare that with just "positive thinking" now. You have a talk and you keep trying to think positive things here and there to feel better. The problem with this approach is that it is too haphazard an approach. Usually the positive thinking is not done in a structured enough way so little to nothing much happens because it has not sunk deep into the subconscious mind and become a real HABIT of confidence.
Simply begin to keep contemplating change and spiritual growth through the understanding of how the conscious mind and subconscious mind work together and you'll really be able to take better control of your life and destiny. There are many ways to master this conscious/subconscious relationship, but for the sake of simplicity, a simple way is to bring awareness to your thoughts and keep thinking of the things you desire with a calm, focused repetition. This is enough to make something sink into this powerful part of your brain known as the subconscious mind.
This is certainly a worthy skill to master because it gives us the ability to create a life and magic and to truly design our destinies.