On the Mac, clicking the Zoom button (the green button in the upper-left corner of a window) does something like the Maximize button in Windows: It makes your window larger. On the Mac, however, clicking the zoom button never makes the window expand to fill the entire screen. Instead, the window grows—or shrinks—precisely enough to enclose its contents.

Of course, if you see the button in the upper-right corner of your window, then you can do even better: You can take that program into full-screen mode, where every last pixel of screen space is put to work displaying your document.