Here’s what Google has to say about running split tests:
Website testing is when you try out different versions of your website (or a part of your website), and collect data about how users react to each version. You use software to track which version causes users to do-what-you-want-them-to-do most often: which one results in the most purchases, or the most email signups, or whatever you’re testing for. After the test is finished you can update your website to use the “winner” of the test—the most effective content.
A/B testing is when you run a test by creating multiple versions of a page, each with its own URL. When users try to access the original URL, you redirect some of them to each of the variation URLs and then compare users’ behaviour to see which page is most effective.Read More