A FocusEvent is a type of event in programming that occurs when a user interacts with a user interface element, such as a button or text field. It indicates that the element has gained or lost focus, which means it is ready to receive input or is no longer active. This event is commonly used in graphical user interfaces to enhance user experience by allowing developers to respond to user actions. In many programming environments, such as Java or JavaScript, developers can listen for FocusEvents to trigger specific actions. For example, when a text field gains focus, a developer might want to highlight the text or display helpful instructions. Conversely, when it loses focus, they might validate the input or save the data.