Adding .Mac services to your system provides a lot of great benefits such as an email address, Web page, and so on. The most useful of the .Mac services is the iDisk. This is space allotted to you on servers that Apple maintains so you can store files there. There are many uses for an iDisk, such as creating Web pages, providing FTP sites, synchronizing files across machines, making your files available from different locations, performing online backups, and so on. Except for delays you might experience because of a slow Internet connection, an iDisk acts much like a disk physically connected to your system.
To use an iDisk, you must obtain a .Mac account. After you have done so, you can configure and use your iDisk.
To learn how configure and use an iDisk, see "Using a .Mac iDisk and HomePage to Create and Serve Your Web Pages," p. 426.