What is the purpose of a namespace in PHP?

The purpose of a namespace in PHP is to provide a way to group related classes, functions, and constants. Namespaces help in organizing code, avoiding name collisions, and creating modular applications. When multiple libraries or pieces of code employ the same names for classes or functions, namespaces allow developers to differentiate between them by qualifying the name with the respective namespace. This capability is particularly useful in larger applications or when integrating third-party libraries, as it ensures that identifiers can coexist without conflict.

By using namespaces, developers can write cleaner and more maintainable code, improving code readability and organization. It enables a structured way of creating APIs and managing libraries, as classes that might otherwise have clashing names can be kept separate simply by assigning them to different namespaces.