APY — short for "annual percentage yield" — is one of the most important numbers you’ll see when shopping for a bank account. It reveals how much you’ll truly earn in one year after compound interest is factored in. Understanding APY can help you spot better savings opportunities and make smarter decisions about where to park your cash. Here's what you need to know about what APY means, how it works, and how to compare accounts with various APYs. What does 'APY' mean? Annual percentage yield — or APY ...