You may not think this is a valuable concern right now in your life, but I ask you to look ahead, much of stretching is about maintaining a quality of life. My health professor sophomore year in college told us a story about when she worked for a health club. She was in charge of a water aerobics class for elderly women. All they did for one hour three days a week was moved their joints and stretch. After a couple weeks the ladies started coming back with all sorts of appreciation and testimonies of what new thing they could do or items they could reach, some of which they had not done for years.
Flexibility is the ability to move muscles through a full range of motion.
For example you could have tight shoulders and flexible hips. Therefore, it is necessary to stretch for specific sports and stretch many joints for total body flexibility. As age increases flexibility decreases, stretching regularly will keep this from happening, to a certain extent. Stretching is only beneficial if done properly. It should be done slowly, regularly, gradually and with correct technique.