A "mouseover" is an action that occurs when a user moves their computer mouse pointer over a specific element on a webpage or application without clicking. This interaction often triggers a visual change, such as highlighting the element, displaying a tooltip, or revealing additional information. It enhances user experience by providing immediate feedback and context. Mouseover effects are commonly used in web design to improve navigation and interactivity. For example, when hovering over a button, it may change color or display a popup with more details. This technique helps users understand the functionality of different elements on a website.