Utility classes: Static classes can be used to implement utility classes that provide common functionalities or helper functions that are not related to any specific instance of a class.

Constants: Static classes can be used to define and store constants that are shared across multiple classes or instances.

Singletons: Static classes can be used to implement singleton pattern, where only one instance of the class is created and shared across all instances that access it.

Factory classes: Static classes can be used to implement factory classes that provide static methods to create instances of different classes.

Math libraries: Static classes can be used to implement math libraries that provide static methods for mathematical operations such as calculating square roots, trigonometric functions, etc.

Logging classes: Static classes can be used to implement logging classes that provide static methods for logging information, warnings, errors, etc.

Configuration classes: Static classes can be used to implement configuration classes that provide static methods for reading and writing configuration settings.

Error handling: Static classes can be used to implement error handling classes that provide static methods for handling exceptions and errors in a consistent manner.