When thinking of stretching there are two main categories to consider, active and passive. Passive involves using external force to facilitate lengthening such as gravity, a partner, straps, etc. Active involves using your own strength and movement to facilitate lengthening, such as in yoga. Passive stretching is very common, but might not be most effective, depending on your situation and goals. An evaluation of what needs to be stretched and why may help you choose the best approach.