A pop-up is a type of window that appears on top of or over the browser window of a website that a user has visited. In contrast to a pop-under ad which appears behind or in the back of the browser window, a pop-up is more obtrusive as it covers other windows and particularly the window that the user is currently trying to read. Pop-ups are primarily used as advertisements on the Web. Pop-ups normally occur after someone has captured the address of your workstation while you were surfing the internet. Contact IOT Customer Service (ICS@iot.in.gov or 234-4357) if the pop-ups have become intrusive and are affecting your productivity.