Unwrapping the Gifted , by Tamara Fisher, is a great article that helps sorts out what gifted is, and what gifted isn't. The author also gives us a peek into what gifted education is all about. Children who are gifted, simply learn differently from their peers. Gifted children do not always get high marks or complete their homework, because they require a different type of teaching to help them succeed.
Take a look at Unwrapping the Gifted, it's an enjoyable light read and explains this topic well, without the usual jargon.