Stretching, in general, can accomplish two things; calming down of excessive muscular activity/tone, lengthening of connective tissue/fascia.
Traditional stretching is two-dimensional (although our body, of course, is three-dimensional) and typically involves stretching a muscle over a joint and involves holding the stretch for a brief period of time (15-30 seconds). Traditional stretching addresses the muscle and the elastic tissue, but not the collagenous, firmer component of our connective tissue. Results are therefore partial and temporary. Lots of people have been diligent about regular stretching for years and still feel stiff and prone to injury!