Saving a document on a disk is like filing a paper document in a file cabinet. How you save a document on a disk depends on the application. Sometimes Save is an option on a menu; sometimes you press a combination of keys that tells the application to save your document. (The manual that came with the application will explain exactly how to save your work.)
Once you've saved your document on a disk, it's OK to quit the application and turn off the computer's power. When you flip the power switch, the copy of the document that was stored electronically in the memory of the computer is lost, but you can retrieve a copy of the document from the disk any time you want to work on it.
Before you can store document on a blank disk, the disk has to be formatted, or initialized. (The terms are used interchangeably.) Formatting a blank disk magnetically divides the disk into numbered "parking spaces" where information can be stored and retrieved. (See Figure 2-7.)
Some applications have a formatting option on a menu within the application. Other applications expect you to format disks by using the System Disk. You'll learn more about formatting in Chapter 4 and in the system disk guide.
Once your document is safe on a disk, you can rest easy. It's just like having a paper copy of your document in a file cabinet. The only reason you wouldn't be able to get it back is if you lost the disk or left it in your shirt pocket through a wash-and-dry cycle. This doesn't happen very often, but it always seems to happen the day before an important deadline with work that is irreplaceable. That's why it's a good idea to save the same document on two separate disks (or on three or four separate disk if the document is really important). Some companies go so far as to store backup copies of important disks in a fireproof safe off the premises. The least you should do is keep your backup copy for enough from the original so that one cup of coffee can't reach both in one spilling.
Disks that contain documents are sometimes called data disks.
Saving a document