What are Django Signals and how are they used in a Django application?

Django Signals are pieces of code that allow certain senders to notify a set of receivers when certain actions occur in a Django application. This functionality helps decouple various components of an application, making it more maintainable and extensible.

In a Django application, signals can be used to perform actions based on various events such as object creation, update, deletion, request/response cycle, user authentication, etc. Developers can define signal handlers that are executed whenever these events are triggered.

For example, a common use case for Django Signals is sending an email notification when a new user registers on a website. By connecting a signal handler to the User creation event, the application can automatically send an email to the user without tightly coupling the email sending logic with the user creation logic.

Overall, Django Signals are a powerful tool for implementing cross-cutting concerns and improving the modularity and flexibility of a Django application.