Sterling is British money, but it also describes anything of very high quality. A sterling report card has all A’s, and sterling manners are needed for a visit with the Queen of England.
Sterling is a word for British currency, and although the jury is still out, the word sterling may be from the Middle English word for "star," sterre from the stars that appeared in the design of certain Norman (really old British) coins. Sterling can still refer to money, but it also describes something great. A sterling reputation is a flawless, immaculate reputation.