Pop-up
A pop-up is a window that suddenly appears on the computer screen, usually on top of the active content of a Web site or program. It is often used to display additional information, advertisements or notifications to the user. Pop-ups can vary in size and can contain either text or images. They can appear when a Web site loads, when you click on a link or when you perform certain actions.
Pop-ups can be useful, such as showing alerts or asking for confirmation for an action, but they can also be perceived as annoying, especially when they appear frequently or show unsolicited advertisements. To prevent unwanted pop-ups, many browsers use pop-up blocking that is enabled by default.
