To "retain" means to keep or hold onto something. For example, when you study for a test, you want to retain the information you’ve learned so you can remember it later. This process is important in many areas of life, such as education, where students strive to retain knowledge for future use. In a business context, companies aim to retain their customers by providing excellent service and quality products. When customers feel valued, they are more likely to return and continue their relationship with the brand. This retention is crucial for long-term success and growth in the competitive market.