Money market funds are a popular investment choice for those looking for a low-risk way to earn a return on their money. Sometimes called "cash equivalents," these funds invest in short-term, high-quality debt securities like Treasury bills, commercial paper, and certificates of deposit. Other common synonyms for money market funds include "liquid funds," "short-term funds," and "cash funds." These descriptive terms all refer to the same type of investment vehicle, which is designed to offer stability, liquidity, and a competitive yield. Whether you're a seasoned investor or just starting out, money market funds can be a great addition to your portfolio.