Manipulators are a type of object that enables a programmer to modify the values of an underlying object without having direct access to that object. In object-oriented programming, manipulators are typically used to encapsulate data so that it can be safely accessed and manipulated by other objects in the system. By using manipulators, programmers can effectively control how data is accessed and modified, making it easier to maintain the integrity of the underlying data. Additionally, manipulators can provide a level of abstraction, allowing programmers to work with data without needing to understand the details of its implementation. Ultimately, manipulators can help to make code more modular and easier to understand.