the.com/beta

means A trial version of something—software, a plan, a person's new haircut—released for testing before it's declared finished, polished, or final.

from From the Greek letter β, the second letter of the alphabet—borrowed by mid-20th-century engineers for a simple reason: 'alpha' testing came first (done in-house, rough and internal), 'beta' testing came second (done with real outside users, still rough but braver). The Greek letters were just a handy, already-ordered sequence for labeling stages—no deeper myth to it, just alphabetical bookkeeping that stuck.