Observer Pattern

The Observer pattern is a design principle used in software development where an object, called the "subject," maintains a list of its "observers." When the subject's state changes, it automatically notifies all registered observers, allowing them to update themselves accordingly. This pattern promotes loose coupling between the subject and its observers, enabling easier maintenance and scalability. A common example is a news agency (subject) that notifies various subscribers (observers) whenever news is published, ensuring everyone receives timely updates without the agency needing to know who the subscribers are.