Compound interest allows money to grow exponentially by earning interest on both the initial principal and accumulated interest. A $1,000 deposit at a 4% annual rate grows to $1,040 in one year, then ...

Interest is the amount of money you must pay to borrow money in addition to the loan's principal. It's also the amount you are paid over time when you deposit money in a savings account or certificate ...

Compound interest can help turbocharge your savings and investments, or it can quickly lead to an unruly balance, keeping you stuck in a cycle of debt. Its magic can help you earn more — or owe more.