A MouseEvent is an event that occurs when a user interacts with a computer mouse. This can include actions like clicking, double-clicking, moving the mouse, or scrolling. Each of these actions generates a specific type of MouseEvent, which can be captured and handled by software applications to create interactive experiences. In programming, MouseEvent objects provide information about the mouse action, such as the position of the cursor and which mouse button was pressed. Developers use these events to trigger responses in applications, enhancing user engagement and functionality in web pages and software interfaces.