Altmer, for example, at more adept at magic than other races. In terms of a comparison, we can say that they are born with more magic, or at least with the capability of using more. An Orc, for example, does not have the ability. But yes, everyone can use magic. But the degree to which varies from race and individuals.
Well, also, Altmer have magic as an inherent part of their cultural heritage. So it may not be a racial as much as a cultural ability, since Altmer girls and boys are likely taught how to magic their bedside lamps on from the cradle while an Orc will be using more mundane techniques long into advlthood.
The martial arts anology was best, I feel. It's easier to learn the younger you start, and some people have a bit more of a natural talent than others, but it isn't something your average person can't learn, even if some people need to train harder to get the same result as another person.