An InputEvent is a type of event in programming that represents user interactions with a device, such as a keyboard, mouse, or touchscreen. It captures actions like key presses, mouse movements, and touch gestures, allowing applications to respond accordingly. In web development, InputEvent is commonly used in JavaScript to enhance user experience by enabling real-time feedback and interactivity. For example, when a user types in a text field, an InputEvent can trigger functions that validate input or update the display dynamically.