Money market funds are a type of mutual fund that invests in short-term, low-risk financial instruments, such as Treasury bills, commercial paper, and certificates of deposit. They aim to provide investors with a safe place to park their cash while earning a modest return, typically higher than traditional savings accounts. These funds are designed to maintain a stable net asset value (NAV) of $1 per share, making them a popular choice for individuals and institutions looking for liquidity and capital preservation. Investors can easily buy and sell shares, providing quick access to their funds when needed.