What is Listeners?

In software development, a listener is a component that waits for and responds to events. It's a design pattern where an object (the listener) subscribes to events generated by another object (the subject or observable). When an event occurs in the subject, the listener is notified and executes a predefined action or function in response. Listeners are commonly used in graphical user interfaces (GUIs) to handle user interactions like button clicks or mouse movements, in network programming to handle incoming connections or data, and in other event-driven systems to react to changes in state or data.