Precalc is typically a review of trig and algebra 2.
College Algebra is typically a remedial class equivalent to algebra 2.
AP Statistics is concerned with analysis of data and various types of ways of analyzing data (for example, a way to calculate whether there is a correlation between two variables and how strong that correlation is). It also covers basic probability. It also covers statistical inference testing. For example, given a set of data (let's say, heights of randomly selected people), you will run a statistical test (and this involves looking at a normal distribution) , and determine with a 95% level of confidence that the actual average height of humans falls within the range of X to Y.
The math in AP Stat is very simple (plug into calculator). It's all about memorizing rules and equations and different situations.