More and more application programmes create temporary files. Their purpose include containing data about a file that is being worked upon. These files often are stripped of their usefulness once the work session ends, and are often removed.
Later versions of the Mac OS gather all temporary files and stores them inside the Trash (Wastebasket) in a folder named Rescued items from... plus the name of your hard drive (e.g. Macintosh HD). Earlier versions of the system, instead, kept them on some other location (e.g. on the root level of the hard drive or startup drive). The Temporary Items folder is also used for this purpose. With Mac OS X, the method is different altogether. Very few temporary files are visible at all, and no Rescued items folder appears, not even in the Trash.
Often, users can tell which application created a temporary by the filename. However, even this can be thwarted if the filename is uncertain or confusing. Some examples of easily-detectable names include:
However, other files, such as Undo File (MacWrite) are harder to detect or to make sense of. Microsoft Word, as of version 6, uses a far less comprehendable name, and temporary files on Mac OS X often use a random combinations of numbers and tilde marks.