Lets related training and development to boxing. Have you seen the movie ROCKY V? Did you notice how they train him? In boxing, an athlete has to focus on lot many things, speed, agility, footwork, handwork, stamina, punches and the whole lot.
Short term objective is to get rocky in shape to fight because he is old and lacks speed and stamina and all of it.. short term objective there is to give him whats necessary to be eligible for the battle such that wouldn't get knocked out in the first round. The long term objective is to concentrate on his area of expertise, cold punches that will make the opponent feel he kissed hot iron.
So, short term T n D, equips the person for a quick fight, long term T n D, focuses on the persons strenghts and accelerates them and tries to reduce his weaknesses so that he wins the battle.
Good enough?