Only one program can be in front, or active, at a time.

To make a different program active, you could simply repeat the technique you used to launch the program initially. Click its Dock icon, double-click a document icon, or whatever.

You can also switch to a different program by clicking its icon in the Dock. Doing so makes the program, along with any of its open windows and toolbars, pop to the front.

But there’s a faster, more direct program-switching feature—faster, because you perform it entirely from the keyboard. Just hold down the key and begin tapping the Tab key (Figure 5-3).

Figure 5-3. Apple calls this Windows-like row of open program icons a “heads-up display,” partly because it’s translucent (like the projected “heads-up display” data screens on a Navy jet windshield) and partly because you don’t have to look down to the Dock to see what you’re doing. (Shown here superimposed on another window to illustrate its translucence.)