What is the term for the hierarchy of classes in OOP?

The term for the hierarchy of classes in object-oriented programming (OOP) is inheritance. Inheritance allows a new class to inherit properties and behaviors (methods) from an existing class, establishing a parent-child relationship between classes. This hierarchy can represent relationships in a way that promotes code reusability and logical structure within the application.

When a class inherits from another, it can utilize and override existing functionalities and add new features, facilitating a clear organizational structure. This is crucial for managing and understanding complex systems, as it allows developers to foster relationships between different parts of their codebase clearly and intuitively. Inheritance forms the backbone of polymorphism as well, enabling objects of derived classes to be treated as objects of their base class, which promotes flexibility in programming.

The other concepts, while fundamental to OOP, do not refer specifically to class hierarchy. Encapsulation pertains to bundling data with methods that operate on that data, abstraction focuses on hiding complex reality while exposing only the necessary parts, and polymorphism refers to the ability of different classes to be treated as instances of the same class through a common interface. Each of these concepts plays an essential role in OOP, but inheritance specifically defines the class hierarchy structure.