A Certificate of Deposit (CD) is a savings certificate entitling the bearer to receive interest. A CD bears a maturity date, a specified fixed interest rate and can be issued in any denomination. When you open a CD, your money is on deposit for a specific time period. For agreeing to keep it on deposit for a specified time period, you earn more than you would in a regular savings account. If you cash it in before its maturity date, you pay a penalty.