Meditation is that which gives you deep rest. Meditation is an activity in which the practitioner just sits and allows the mind to dissolve. In Art of living ,meditation is a simplified activity which can easily be practiced by all. Meditation is not concentration. It is de-concentration, says its founder, Sri Si Ravi Shankar.
The rest in meditation is deeper than the deepest sleep that you can ever have. When the mind becomes free from agitation, is calm and serene and at peace, meditation happens.