Power is how fast you can apply strength. In order to throw harder, throw farther, swing faster and hit with more power, you have to be both strong and fast, and you must be able to apply force (strength) quickly.
If you are a young baseball player (or the parents or coach of a young baseball player) who wants to become a better player, you MUST become a better athlete. To become a better athlete, you MUST get stronger, run faster, increase power, improve agility and become more flexible. Baseball skills are important, but to be truly successful, you MUST be able to perform baseball skills under control with coordination, strength, speed and power.
What good is it to be able to make bat contact if you aren’t strong enough to drive the ball into the outfield? What good is it to be able to field and throw perfectly, if you’re too weak, too slow or lack the strength and agility to get to balls more than two feet away and then be able to stop, field the ball, set your feet and throw with enough speed to get the runner out?