As others have said, much depends on what you plan to do that year.
If you decide to take a gap year then be careful to find out for colleges you are considering if taking a class or two (which some students might want to do just to keep their hand in academic waters) is ok. For example at the UC schools if you take even one community college class during that gap year then you are no longer eligible to apply for frosh admission.
Also some colleges offer admitted students the opportunity to defer admission for a year. For example Harvard used to make that offer in their admission letters to every student (don’t know if they still do, but I doubt it has changed).