As the old saying goes, there are two kinds of people: those who have a regular backup system—and those who will.
You'll get that grisly joke immediately if you've ever known the pain that comes with deleting the wrong folder by accident, or making changes that you regret, or worst of all, having your hard drive die. All those photos, all that music you've bought online, all your email—gone.
Yet the odds are overwhelming that at this moment, you do not have a complete, current, automated backup of your Mac. Despite about a thousand warnings, articles, and cautionary tales a year, guess how many do? About four percent. Everybody else is flying without a net.
If you don't have much to back up—you don't have much in the way of photos, music, or movies—you can get by with burning copies of stuff onto blank CDs or DVDs (Chapter 11) or using the .Mac Backup program described at the end of this chapter. But those methods leave most of your Mac unprotected: all your programs and settings, not to mention Mac OS X itself.
What you really want, of course, is a backup that's rock-solid, complete, and automatic. You don't want to have to remember to do a backup, to insert a tape, to find a cartridge. You just want to know that you're safe.
That's the idea behind Time Machine, a marquee feature of Leopard. It's a silent, set it-and-forget-it piece of peace of mind. You sleep easy, knowing there's a safety copy of your entire system: your system files, programs, settings, music, pictures, ...