An event listener is a programming component that waits for specific actions or changes within a system. In the context of cryptocurrency applications, it monitors events such as transactions, block confirmations, and changes in wallet balance.When a relevant event occurs, the event listener triggers predefined actions, such as updating user interfaces, sending notifications, or executing trades. This functionality is crucial for building responsive and interactive applications, like wallet software or trading platforms, allowing users to receive real-time updates.Event listeners can be built using various programming languages and frameworks, adapting to the needs of different applications. For example, in web-based applications, listeners can respond to user interactions while also monitoring blockchain events through APIs.Overall, event listeners enhance user experience and improve application efficiency by automating responses to significant changes, ensuring that users remain informed and engaged.