Multiple Desktops allows you to have multiple screens (desktops) on one monitor. This allows you to have a full screen of programs open for one task, and open a blank screen to do another. Perhaps one is for sending an email and another is for a game.
Both Windows and Linux have multiple desktops. I have Windows 11 and Linux Mint, so I will tell you how to use them.
Windows 11
Click the Multiple Desktops icon 
on the Windows Taskbar, and click New Desktop. You now have a new, blank desktop. Click the Multiple Desktops icon again, then click Desktop 1, and you’re back.
You can do this again, and create more desktops.
You can quickly navigate between Multiple Desktops by typing Ctrl + Start Key + Left Arrow and Ctrl + Start Key + Right Arrow.
To change your background, you can go to personalization-background.
Linux Mint
In Linux, these are called Workspaces. Type Ctrl + Alt + Up Arrow to get to the screen where you can add new workspaces and subtract some. Click the plus sign on the right to add a new workspace. Click the minus on the upper right of the workspace icon to delete the workspace. Type Ctrl + Alt + Down Arrow to return.
You can now navigate between each of these workspaces easily. Type Ctrl + Alt + Right Arrow and Ctrl + Alt + Left Arrow to switch between them.
You can find the setting for this by clicking Menu –> Preferences –> Workspaces.
Enjoy your new space.
I like to make different backgrounds and different icons for different workspaces. You can learn how to do that at https://forums.linuxmint.com/viewtopic.php?f=42&t=360221 (archived version). This gets a little geeky. As you may know, I recommend using Linux Mint, Cinnamon Edition. Instead of creating the three files mentioned in the article for Cinnamon, you can download this .tar.gz file. It has the three files you need.
Move Window To Another Workspace
To move a window from one workspace to another workspace in Linux Mint, first make the window active (click on it). Then, to move the window to a left workspace, type Shift + Ctrl + Alt + Left Arrow. To move the window to a right workspace, type Shift + Ctrl + Alt + Right Arrow.
