Inversion of Control (IoC) is a design principle used in software development to improve the flexibility and maintainability of code. Instead of a program controlling the flow of execution, the control is inverted, allowing a framework or external entity to dictate how components interact. This approach helps to decouple components, making it easier to manage dependencies and swap out implementations without altering the core logic. One common implementation of IoC is through Dependency Injection, where dependencies are provided to a class rather than the class creating them itself. This allows for better testing, as mock objects can be injected during unit tests, and promotes a cleaner architecture by adhering to the Single Responsibility Principle.