The phrase "alpha testers" refers to a group of people who use a product or software before it's officially released to the public. They help to identify any problems, provide feedback, and assist in improving the product. Full definition
Alpha tester here: That's exactly how it works. (n4g.com)
Below you can find more stunning numbers achieved by Alpha testers. (dualpixels.com)
As a part of its new Inside Xbox video collection, Microsoft introduced plenty of updates coming to Xbox One later this spring, and Xbox Insider Alpha testers for the console can take these options for a spin proper now. (skilledgeekz.com)