Explain the purpose and function of access modifiers in object-oriented programming

Access modifiers in object-oriented programming define the level of visibility and accessibility of class members (variables, methods) to other parts of the program. The main modifiers:

• public — accessible everywhere, can be accessed from anywhere.
• private — accessible only within the class itself.
• protected — accessible within the class and its subclasses.

This allows encapsulating data, hiding internal implementation details, and protecting them from improper use. For example, private class fields cannot be changed directly, only through public methods, which ensures control over the object's state.