A Required Minimum Distribution (RMD) is a mandate that requires you to start withdrawing funds from your IRA at a certain age. Even if you prefer to keep the money in your IRA, you must begin taking distributions once you reach the required age.
For more information on RMDs and how they apply to different types of IRAs, please refer to the linked IRS page below:
Retirement Topics — Required Minimum Distributions (RMDs) | Internal Revenue Service (irs.gov)