. . . a single correct answer to a particular question. (e.g. "What's the best way to make tomato soup?" or "What's the best comedy programme programme on television?" will get different answers from different people, all of whom believe that their answer is the best one)
However the 'regulars' around here try to ensure that they only base their 'researched' answers on reliable sources, so most answers are generally reliable.
(PS: I've no idea why my computer submitted answers above without me ever clicking on 'Answer Now'!)