What are Pop-up ads!!

 Are a form of online advertising on the World Wide Web intended to increase web traffic or capture email addresses. It works when certain web sites open a new web browser window to display advertisements. The pop-up window containing an advertisement is usually generated by JavaScript, but can be generated by other means as well.

A variation on the pop-up window is the pop-under advertisement. This opens a new browser window, behind the active window. Pop-unders interrupt the user less, but are not seen until the desired windows are closed, making it more difficult for the user to determine which Web site opened them.

Non-browser pop-up ads

Processes other than the Web browser can also display pop-up ads, or can direct the browser to display them. Many spyware programs do this, as well as some advertising-supported software, although the line between the two is sometimes thin.

A different sort of pop-up ad can be sent via the Messenger service in Microsoft's Windows operating system. These pop-ups appear as Windows dialog boxes with a textual message inside, usually directing the user to a Web site. Claims have been made that this type of pop-up has been used to commit extortion. Threats of legal action against the company D Squared Solutions has caused them to stop using this technique.