What is the difference between AP classes and Advanced Classes in high school?

Gifted classes are for those who either have certain conditions that need to be met or are considered quite smart for their age.

AP, or advanced placement, classes are more or less classes preparing you for an advanced level of work. AP Calculus or AP Biology prepare you for college and have the chance to give you credit for the courses, this way you won't have to take them during your enrollment in college.