The DRY (Don’t Repeat Yourself) principle in software engineering is a programming concept that emphasizes the importance of avoiding code duplication. The principle states that “Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.” This means that any information or logic should be defined in a single place in the code and should be reusable across the entire system.

By following the DRY principle, developers can ensure that code is easier to maintain, update, and test, since any changes or updates can be made in a single location rather than being scattered throughout the codebase. This approach can also help reduce the likelihood of errors and inconsistencies in the code. In short, DRY principle aims to promote efficiency, maintainability, and readability of the codebase.