To me, skill goes beyond physical ability. I think that skill goes deeper than that. It goes straight to the heart. Without passion or love for something, there is no skill behind it. Heart is what drives a lot of people, I won't say most people because I have no way of proving that. It doesn't matter what it is that someone is skilled at. It can be a game, a job, talking to people, anything.
I also believe that skill can be earned, developed, or born with. We didn't come into this world knowing how to speak, and that is a skill in and of itself. While some people may have artistic talents, others don't. They may strive to learn how to do it and either succeed or fail, but that can be a skill that developed or born with. Being a leader is another prime example of skill and I think it can fall into all three categories. You can earn the skill to lead by proving yourself to others. You can develop the skill to lead by learning from others. And sometimes, people are just born to lead.
I see it everyday in the people around me and it amazes me every time. Some people take it for granted and never even reflect on the things they do, while others have the desire to brag and boast to everyone around them about what they have done. Then there are those few who quietly acknowledge a feat, smile, say thank you to someone who notices it, and move on through their lives impacting other people without even really trying.