Pop-up ads are online advertisements that appear suddenly on a website, often in a new window or tab. They are designed to grab the user's attention and promote products, services, or special offers. While some pop-up ads can be informative, many users find them intrusive and annoying, leading to the use of ad-blocking software. These ads can be triggered by various actions, such as clicking a link or simply visiting a webpage. Pop-up ads are commonly used by marketers to increase visibility and drive traffic to their websites, but their effectiveness can vary based on user experience and preferences.