Thank you for your question!
I will explain from the “dictionary” of my experience. Meditation is to heal the self by complete awareness of the being. This meditation is not just to sit down, but it can be done, “while walking and moving around.”
When we are learning the “feel” of mediation, we can perceive thoughts, feelings and bodily sensations coming in the way. Through concentration, we can be “single pointedly” in our purpose, which is to “feel” the self. Then, the rest becomes background noise as long as you can hold that concentration or when that concentration becomes “contemplation,” that is the awareness and experience of the blissful self. Those “stages,” could be just summarized on consciousness of the being, the self; that is soul consciousness. That brings healing, changes and that is self-transformation in itself.