As you're certainly aware by now, Mac OS X's resemblance to the original Mac operating system is only superficial. The engine underneath the pretty skin is utterly different. In fact, it's Unix, one of the oldest and most respected operating systems in use today. The first time you see it, you'd swear that Unix has about as much in common with the original Mac OS as a Jeep does with a melon (see Figure 16-1).
What the illustration at the bottom of Figure 16-1 shows, of course, is a command line interface: a place where you can type out instructions to the computer. This is a world without icons, menus, or dialog boxes. The mouse is almost useless here.
Surely you can appreciate the irony: The brilliance of the original 1984 Macintosh was that it eliminated the command line interface that was still the ruling party on the computers of the day (like Apple II and DOS machines). Most nongeeks sighed with relief, delighted that they'd never have to memorize commands again. Yet here's Mac OS X, Apple's supposedly ultramodern operating system, complete with a command line! What's going on?
Actually, the command line never went away. At universities and corporations worldwide, professional computer nerds kept right on pounding away at the little C: or $ prompts, appreciating the efficiency and power such direct computer control afforded them.
You're forgiven if your reaction to the idea of learning Unix is, "For goodness'sake— can't I finish learning one way ...