A popup window is a window that is smaller than standard windows and typically does not contain some of the standard window features such as tool bars or status bars. Popup windows display when users hover over or click on a link. The popup topic closes automatically as soon as the users clicks somewhere else.

A typical use of popups is to display glossary terms. For example, in a printed document, terms and definitions are typically grouped in a separate glossary document. However, in a help system, you can display glossary definitions in popups. When you create glossary popups, users can choose whether they want to view the definition of an unfamiliar term. If they want additional information about the term, they can view the definition in a click.

You create popups by creating link between the word or phrase in a topic and the content you want to display in the popup, and then you use <othermeta> elements or paragraph styles to create popups.