Description: The internal iterator is a design pattern that allows a collection to control its own iteration process. Unlike an external iterator, where the client has control over the iteration loop, in the internal iterator, the collection takes care of the iteration logic. This means that the client simply provides a function or block of code that will be executed for each element of the collection, while the collection handles traversing its elements. This approach promotes greater encapsulation and reduces the complexity of the client code, as it does not need to worry about the details of how iteration is performed. Additionally, the internal iterator can optimize the iteration process since it has direct access to the internal structure of the collection. This pattern is common in programming languages that support higher-order functions, such as JavaScript, Python, and Ruby, where functions like `map`, `filter`, and `forEach` can be used to operate on collections in a more declarative and concise manner.
