We use these windows to expand on terms used in the text, allowing us to keep our pages concise while providing more detail for anyone who is interested.

Pausing the mouse pointer over the pop-up symbol should provide a short summary of the pop-up's content.

Some pop-ups contain Flash animations. If your browser doesn't support Flash you will get static or animated gifs which serve the same purpose but are poorer quality in order to minimise download times.