A/B testing (sometimes called split testing) is comparing two versions of a promotional tool 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 one that gets a better conversion rate, wins.
A/B Testing: The Method That Works
A Custom, Easy-to-Use Popunder Script Perfect for SPLIT TESTING
The Complete Guide to A/B Testing