To rate something is to judge how good it is and give it a score or a place on a list. Top-rated means a lot of people gave it high scores, so it sits at or near the top of such a list. 'The top-rated restaurant in town', 'a top-rated TV show', 'top-rated hotels on the website'. Two slightly different flavours live inside this one word. In television it grew up meaning 'watched by the most people' — a top-rated show is the one with the biggest audience, which is about numbers, not quality. Online it now usually means 'given the most stars by reviewers' — a top-rated seller, a top-rated app. Both share the same idea: other people judged it, and it came out high. That is the honest limit of the word. It does not say the thing is good; it says the crowd said so. A film critic might hate a top-rated show. It comes before a noun almost always, and it belongs to easy everyday English — shopping sites, entertainment news, travel pages.