What type of inheritance occurs when multiple subclasses inherit from a single superclass?

When multiple subclasses inherit from a single superclass, the inheritance is referred to as hierarchical inheritance. This type of inheritance structure creates a tree-like hierarchy where one parent class (the superclass) can have multiple child classes (subclasses). Each subclass can inherit properties and behaviors defined in the superclass, allowing for code reuse and a clear organizational structure.

In hierarchical inheritance, the subclasses can also have their own specific attributes and methods while still sharing common features from the superclass. This is particularly useful in scenarios where several classes require the same foundational characteristics but need to extend or modify them for their specific use cases.

By contrast, multiple inheritance involves a subclass inheriting features from more than one superclass, resulting in complexity such as the diamond problem. Single inheritance only allows for one subclass per superclass, making it simpler but less flexible than hierarchical inheritance. Lastly, multilevel inheritance structures involve a chain of inheritance, where a subclass itself serves as a superclass for another subclass, thus creating additional layers of hierarchy.