Retention Rate is a measure used to determine how many customers or users continue to engage with a business or service over a specific period. It is often expressed as a percentage and helps companies understand their ability to keep customers satisfied and loyal. A high retention rate indicates that customers are happy and likely to return, while a low rate may signal issues that need addressing. For example, a subscription service like Netflix tracks its retention rate to see how many subscribers renew their memberships each month. By analyzing this data, Netflix can identify trends, improve user experience, and develop strategies to enhance customer loyalty.