This is a new window that was opened when you clicked on the link. If you minimize this window you will see the one you came from and the link will be orangered in color. Of limited use in the design of your page unless you:

1. use it to work with a framed page or
2. as in this case a new window

In these two cases it will help your visitor keep track of where they are and what they are doing. In the event they are moving from single page to single page, say from an index page to a page listed in the index, the link to the last page visited will turn to the alink color when the cursor touches the link on the index page.