A pop-up ad is a type of online advertising that is displayed in a separate window or frame on top of a website or app. Pop-up ads are typically triggered by user actions, such as clicking on a link or button, or by timed intervals, such as after a certain amount of time has elapsed on a page. Pop-up ads can be an effective way for advertisers to deliver their message to users, and to engage and interact with their target audience. Pop-up ads can also be beneficial for publishers and platforms, as they can provide a new source of revenue and a valuable source of content and engagement for their audience. However, pop-up ads can also be disruptive and annoying for users, and can lead to a negative user experience if they are not implemented in a responsible and transparent way.