Active Users?
 

On the Forums front page, there is a space that tells you which members are currently "active".....
Now, does this mean that the members listed are actually viewing the site at the moment, or does it simply mean that they are online, in general, and not necessarilly at the Wavefront?

At the website. I don't know about you, but I am always online. I'd have to unplug my computer from the wall to be disconnected.

Correct.

Unless the forum itself has a certain user listed as online, then said user is not visiting the W. A user may decide to remain invisible to the forum population, but they are always visibie to administrators.