The "touchmove" event is a type of event in web development that occurs when a user moves their finger across a touch-sensitive screen, such as a smartphone or tablet. This event is part of the Touch Events API, which allows developers to create interactive applications that respond to touch gestures. When a "touchmove" event is triggered, it provides information about the movement of the touch point, including its coordinates. Developers can use this data to implement features like dragging, scrolling, or drawing on the screen, enhancing the user experience in applications and websites.