Mind is divided in two parts conscious and subconscious mind.

Conscious Mind :

The conscious mind is the part of your mind that is responsible for logic and reasoning. When I ask you about the sum of three and four, it's your conscious mind that you use to get the addition done. When you decide to take any voluntary action like moving your hand or leg, it is done by the conscious mind. So, whenever you are aware of the thing you're doing or want to do, it's done with your conscious mind; whenever there's logic or reasoning to be done, you use your conscious mind.

Subconscious Mind :

The subconscious mind is the part of your mind responsible for all of your involuntary actions like emotions, your heart beat or your breathing rate. Your subconscious mind is also the storage room of all your beliefs and memories. That’s why changing beliefs and unwanted emotions can be done through hypnosis; sending suggestions to the subconscious mind.

The subconscious mind exists outside of the conscious mind but can be controlled by conscious decisions.

The subconscious mind is formed very early in life, basically from the time you were an infant. A large part of your subconscious was shaped with what you heard, what you saw and what you experienced as a young child. As a child your emotions are much more fragile then as an adults, therefore this is where most of the subconscious part of your mind is shaped and formed.

There is no right or wrong or true and false for the subconscious mind. This is a fundamental thing to understand about the subconscious mind in order to be able to use it for you own benefit.

Think of the subconscious mind as the storage room of everything that is currently not in your conscious mind; it stores all your previous life experiences, your belief system, your memories, your skills, all situations you've been through, and all images you've ever seen. The best way to understand the subconscious mind is through the example of someone who's just started to learn how to drive. At the beginning, he wouldn't be able to hold a conversation with anyone while driving as he would be focusing on the different moves involved; that's because he's still using his conscious mind to drive.

A few weeks later, the driving process comes to him automatically, without having to do any thinking; he'd even start using his cell phone or talk to his friends as he drives. This on account of the fact that the driving information or process has been transferred to his subconscious mind and so the conscious mind is free to function on something else, like talking or using his cell phone.

Why do we say everything is true for the subconscious mind? Because the conscious mind can define between something that is so or not, but the subconscious part of you cannot. Let me give you a perfect illustration of that effect. When you are watching a movie, you, that is “the conscious mind of you” knows that everything happening in the movie is false. The actors are not who they pretend to be, the dead are not dead… nothing is real, yet, if the story is sad you, that is “the subconscious mind of you” cries. At that point even if you are aware “consciously” that it is just a movie that you are watching, you “subconsciously” believe that is true.

This phenomenon is due to the fact that our subconscious more than our conscious is directly related to our emotions, and in turn our emotions are the vehicle of our subconscious mind. Our emotions being so strong as a child it shapes our subconscious very strongly as well.

The problem with this is that many of the things that our subconscious learns when we are just a young child, is false. Here is an example of that. If you have a parent or a teacher that has told you that you were not smart. Regardless of being true or false your subconscious believed it. If you didn’t do anything to change your subconscious mind about this matter, you would “subconsciously” ALWAYS believe it even if “consciously” you knew that it wasn’t the truth. The only way to remedy to this problem is the CHANGE the belief that is deeply engraved in your subconscious mind.

There is a simple exercise that you can do in order to make the difference between the conscious and unconscious mind clear. Change your breathing rate to either faster or slower, what you are doing now is using your conscious mind to breath. Now stop controlling your breath and let it flow naturally. When you forget about this exercise, you will notice how your subconscious mind returns your breathing rate back to normal, contrary to when you had your conscious mind control the process.

Using your conscious and subconscious mind together :

As you can see, the conscious and the subconscious parts of the mind form a team. The first handles some tasks then assigns them to the second, the second after that sends feedback and messages about the task done in the form of emotions to the first. Emotions are no more than messages sent by your subconscious mind in order to alert you of something. By learning how to make the best use of the cooperation between your conscious and subconscious mind, your life skills will improve and you will have much more control over your emotions.

Ego defense mechanisms :

Just like your body has got its defenses against physical wounds and injuries, your subconscious mind has got its defenses against emotional shocks and wounds. These are called ego defense mechanisms or unconscious defense mechanisms. The ego defense mechanisms' main function is to protect your well-being and to help you overcome emotional shocks.