The area between the anus and the vagina is burning and red what is it?

It could be number: Of things . The area you described is called perineum . Perineum redness and pain is an indicative of inflammation . Inflammation can be caused in several ways . The big one and that you should be concerned is infection . The other are irritation due to urine and or other irritants . I suggest you see family doc if it is not going a way say in the next couple of days . Good luck.