Skill is applied knowledge. It's when you know something and can use it over and over again - a little like programming a computer to perform certain functions. That's skill. Some teachers are apposed to skill because they believe it kills creativity. But, in fact, it's the opposite - skill gives you the capacity to create.
Creativity takes place in the unknown - the discovery of a form or image not yet manifested. It is why artists make art. Consider Van Goch in the last 70 days of his life - he created about one painting a day. Why? It doesn't seem his motivation was money. Just imagine coming each day with a painting, propping it up on the bed, and wondering where the image come from. I believe what motivates him to go out the next day and paint again and again was the excitement of not knowing what was going to happen next.