Mac Spaces is a great feature that allows you to virtually have dual, triple, quadruple monitors (or more) on your Mac. Mac Spaces works by creating desktops where you can place program windows, allowing you to organize your running programs and open windows into logical “groups” or “themes”.
An easy way to imagine how Spaces works is to think of your display or monitor as a box with four sides. When you look at one side of the box, the other sides are hidden or out of view. On each of the four sides you can post pieces of paper, spread sheets, web pages, emails, etc. On each of these “sides” it would make sense to put certain programs together to follow a theme. For example, one side of this box could be dedicated to communications (Mail and instant messaging). Rotate the box to the right to see the next side. Now you have another empty space on which to put more running programs, such as iTunes.
The power behind this is that you don’t have a deep stack of program windows placed on top of one another and you can switch to viewing these “Spaces” where programs are fully visible beside one another, grouped into logical themes, all available with a quick button press to switch Spaces.
The majority of your time working (or playing) on your Mac is spent focusing on one thing, window or program at a time. The rest of the programs that you keep running such as iTunes or Mail are kept running because you refer to them from time to time, but you don’t need to stare at your email inbox waiting for mail to arrive you just check it periodically, which makes sense in terms of efficiency.
By default, Mac Spaces is not turned on. To enable Spaces, go to System Preferences => Exposé & Spaces => click Spaces tab on the middle top center (right beside Exposé which is blue highlighted), then check the checkbox on the left to Enable Spaces.
Moving between spaces takes a little time to get used to. Command + 2 moves to Space 2, Command + 3 moves you to Space 3, etc. Control + Down Arrow moves to the next lower space, wrapping back to the top if you’re already at the bottom. You can also press F8 to go into “hover view” where you see all of your spaces on the desktop (like the first screenshot up above) whereupon you can choose a Space to move to by mouse clicking on it.
To move windows in Mac Spaces from one Space to another I find it easiest to put your mouse cursor on the title bar area of the window (where the name of the window is) then click and hold the mouse button, click and hold the Control button on the keyboard, then press one of the arrow buttons, depositing the window into that Space. You can also click and drag the window itself to one of the edges of your display, wait until it switches to that Space, then let go of the mouse button to deposit it into that Space. Being a hotkey freak myself, I prefer the mouse + control + arrow key combination which I find faster and more accurate.