Like its cousins, Windows 2000 and XP, Mac OS X is designed from the ground up to be a multiple-user operating system, thanks to powerful software underneath its flashy exterior. You can configure a Mac OS X computer so that everyone must log in—that is, you have to click or type your name, and enter a password—when the computer turns on. Upon doing so, you discover the Macintosh universe just as you left it, including these elements:
Your documents, files, and folders
Your preference settings in just about every program you use: Web browser bookmarks and preferred home page; desktop picture, screen saver, and language; icons on the desktop and in the Dock; the size and position of the Dock itself; and so on
Your email account(s), including personal information and mailboxes
Your personally installed programs and fonts
Your choice of programs that launch automatically at startup
Accounts in Mac OS 9 work somewhat similarly to Mac OS X's account system, except they're not quite as protective of the files and folders on your computer. Throughout this chapter, you'll see separate explanations of how to set up and use accounts in Mac OS 9.
This user account system means that several different people can use your Mac throughout the day, without disrupting each other's files and settings. It also protects the Mac from getting fouled up by mischievous (or bumbling) family members, employees, and hackers.
But user accounts also have another important purpose ...