Certificates of deposit, or CDs, pay a fixed rate of interest for a fixed period of time, usually a few months to several years. Typically, the longer the time frame, the higher the interest rate. The interest rate on a high-yield savings account is variable, meaning it can change at any time. Another difference between a high-yield savings account and a CD is accessibility. If you withdraw funds before the CD matures — that’s when it reaches the end of the guaranteed rate period — you’ll pay an early withdrawal penalty equal to a certain number of months of interest. With a high-yield savings account, you can access your money at any time without penalty, although federal rules limit the number of monthly withdrawals to six. (This rule was temporarily lifted during COVID-19.) Bottom line, CDs are better for people who are looking for a guaranteed fixed rate of return for a defined period and don't mind forgoing accessibility to get it.