A/B testing or split testing is comparing two versions of a web page to see which one performs better. You compare two web pages by showing the two variants (let's call them A and B) to similar visitors at the same time. The goal of A/B testing is to identify changes to web pages that increase or maximize an outcome of interest (e.g., click-through rate for advertisement). A/B testing is a way to compare two versions of a single variable typically by testing a subject's response to variable A against variable B, and determining which of the two variables is more effective.
With Cetera CMS you can create and track A/B-tests semi-automatically.