There are two ways that the offense can advance the ball down the field, rushing(running) or throwing. Generally the more advanced players in the NFL throw the ball more than College and High School teams. Youth football throws the ball rarely because it requires a skilled quarterback and orchestrated blocking and route running by his team mates. Throwing a football is a learned skill that anyone can learn.
The feet to the hips to the shoulders to the elbow is a pretty good description of proper throwing mechanics. It all starts with the feet and if they aren’t where they need to be, often you will see an errant throw. More than any other postion in any other sport, playing QB and throwing the football effectively relies solely on the proper throwing mechanics.