Interesting question. I reckon that Art in general is a process of self-expression and that creativity is but one element of a range of 'artistic' abilities. However, there are several other aspects that define you're artistic ability. In your chosen field, be it painting, music, film, drawing etc., you need to have a certain level of skill. Skills can be learned, and often your level of skill in any given area limits what you are able to do. You also need a level of talent. Talent is a much less tangible quality - I'd describe talent as your inate ability, or your 'natural skill'. But talent is often difficult to spot, since the only way to discover if you have a talent for something is to try it out.
What sets creativity apart from raw technical ability, however, is how you combine the two aspects of skill and talent, with an additional element of originality. This aspect - originality - requires several attributes as well: knowledge of your subject, experience and the ability to think differently. The first two you can learn to a large extent by simply practicing, and learning about your chosen field. The latter, however, is harder to do, and I feel that this comes under the category of 'inate ability'.
Often you'll find that you're creativity is limited by one or more aspects, but usually the more technically skilled you are, the fewer limits you have on your creativity. For example, if you 'create' a song in your head, like a complex guitar solo, your technical skill at playing the guitar is the limiting factor as to how well you are able to translate that idea into reality. I think this goes for most things. However, with experience and a bit of lateral thinking, a creative but mediocre guitar player can still fashion something that sounds good, despite their lack of technical skill. For me, that's the essence of creativity, and the basis of art itself.
