Namaskaras are salutations. They are a form of prostration. Salutations also warm up the body, establish a link between the breath and the body, and focus the mind.
Forward folds can be done in both a dynamic way [yang] or in a passive way [yin]. When done in a dynamic way we are creating the alignment mentioned above with action, using muscular strength and fascial contraction. This mode should be done with a great deal of focus on keeping the alignment precise, but should only be done in short sessions for instance just holding for five to ten breaths at a time. This type of action creates functional strength and stability.
When forward folding in a passive way, the alignment is supported. For instance, you may use a blanket to rotate the hips forward, a bolster to support bent knees, and two blocks to hold the feet. Once the body is entirely supported, in the position that you want to create [proper alignment], then the body is completely relaxed, especially relaxing the tissues in the body that you are trying to change. Practicing in this way requires that the tissues that you want to change [by stretching or releasing] be completely malleable, completely relaxed, and then staying that way for a long time, maybe three to five minutes. This type of action creates space in the body by breaking of fascial adhesions and lengthening connective tissues.