A "wrapper" or "container" is a software design pattern that encapsulates a specific functionality or data structure, allowing it to be used more easily within a program. This approach helps manage complexity by providing a simplified interface for interacting with the underlying components, making it easier for developers to work with various elements without needing to understand their inner workings. In programming, wrappers can be used to enhance existing functions or classes, adding new features or modifying behavior without altering the original code. Common examples include JavaScript wrappers for API calls or Python decorators that add functionality to functions or methods.