What is the full form of "CD"?

A certificate of deposit (CD) is a product offered by banks and credit unions that provides an interest rate premium in exchange for the customer agreeing to leave a lump-sum deposit untouched for a predetermined period of time. Almost all consumer financial institutions offer CDs, although it’s up to each bank which terms it wants to offer, how much higher the rate will be compared to the bank’s savings and money market products, and what penalties it applies for early withdrawal.