Virtual desktop software nSpaces (free/donationware) provides four virtual workspaces, or spaces that you may split your applications and documents between. For instance, you could have your word processing stuff on one desktop, your spreadsheets on another, your email application and messages on the third, and a movie on the last. The idea is to organize your work and reduce clutter.
Alas, while nSpaces is stable (unlike the far slicker Finestra Virtual Desktop), it's also rather primitive in comparison. It's easy to switch desktops if you use nSpaces hot keys. Not so much if you use the system tray menu. Using the tray requires at least two steps: Right-click the nSpaces icon, then select the space or launch the switcher then choose one of the four spaces there.
I suggest that you take advantage of nSpaces's ability to let you define a different background for each space. There's no precise preview of the virtual desktops with their applications and open windows as with Finestra Virtual Desktops. Instead, only the desktop background image differentiates them. Changing the solid blue background nSpaces defaults to won't cut it--the background will still be black, or blank. Alas, the program also seemed to lose my choice of backgrounds at one point, and to be honest, I'm not sure why.
All in all, nSpaces works well, but is more difficult to use than it should be. Hopefully, future versions will be friendlier. It's free to use, and if you see promise, you can donate to the developer to help out.