SOLVED -- What is the purpose of multiple desktops?

[Magruder]

Pardon the stupid question, but since I honestly don't understand this feature I thought I'd ask.

Why and how do you use multiple desktops?

If I open my browser, or OpenOffice, on desktop 1, and then switch to desktop 2 and start the browser, I find myself in the already-opened session, and back on desktop 1. I had envisioned separate and distinct instances of the browser and OO, with different sites and documents open, but that doesn't seem to be possible.

Several times when I've moved an open window to the side, I moved it far enough that it shifted to the other desktop. What would be the reason to move a window to the other desktop?

There must be some use for this that just hasn't occurred to me. What am I missing?

UPDATE:
After reading the responses below, I started experimenting, and found that I really like the multiple desktops.

The default is two desktops. I changed JWM to use four. I'm now typically using one desktop for an internet browser or two, another for my to-do list and a text document or spreadsheet, and a third for a terminal window or a Rox session.

Doing this with multiple desktops lets me leave three or four different “screens

[Gander22h]

Personally I don't use the multiple desktops, but virtually all Linux desktops have them. Ubuntu 10.10 comes with four as default and you can add more if you want! I am guessing here, but I think the point is to have different applications open on different desktops, so you can switch between them quickly. If I open my browser on the second Puppy desktop, it is a new browser instance. I guess you could use Alt+2 as a "boss key" with what you are supposed to be working on (ie the budget spread sheet) while doing Facebook on desktop number one. Perhaps someone who regularly uses the second desktop can better explain its utility?

[Béèm]

When I have a browser open on a certain page, go to the other desktop and start the browser again, I have the defined home page and not the page opened on the other desktop.

You can open other applications on desktop two in order not to have a crowded desktop on the first one.

Other then that I don't see another use.
Personally I don't use the second desktop.

[UndeadSamurai01]

I do tend to use it, it's just useful to have things separated, like if I'm installing stuff/ transferring files in one window and browsing the web in the other. It saves alot of confusing minimizing and opening. It's not really essential.

I find it especially useful for programing (at which I am presently a n00b), when I have all the class windows open it's easier just to keep them arranged on their own desktop, so I can read documentation from one and work on the program on the other.