Harry,
I could always be wrong about this, but per my (limited) understanding this referred to alternate desktops . . . which could have totally different stuff on it . . . with the ability to rapidly switch between them. You might think of this as a partial, pseudo replacement for having two or three monitors, allowing you to have panoramic displays &/or lots more open app.s, each at a decent size. The products from a company called Stardock -- Object Desktop and Windowblinds -- may have provided this functionality to earlier versions of Win as add-ons.
In eCS, there is a grid at the lower left of the screen, for navigating between these desktops, and indicating which one you were currently in. I found it all rather confusing, and so abstained from using this. In either OS, I get by with a single desktop.
Jordan
From: Harry Binswanger
To:
xywrite@xxxxxxxxxxxxx
Sent: Friday, August 22, 2014 1:07 PM
Subject: Re: It's apparently closer than I thought . . .