Meditation is about increasing your peace. But it is a super-conscious happening, not a manipulation of the brain. It rises above thought. You may say that falling asleep is peaceful, but nightmares can come because it is beyond our control. In meditation, you are watchful and alert, yet in deep peace.
You will know when you are on track because your consciousness will become expanded yet at rest. It is not an easy state to describe but when you achieve it, it is unmistakable. It also has long-lasting effects throughout your day.