What Quicken refers to as a file is really a set of data and index files with the same filename, such as HOME, but different file extensions, such as QDF, QPH, QEL, and QSD. So when Quicken refers to the HOME file, it really is referring to the set of files that includes HOME.QDF, HOME.QPH, HOME.QEL, and HOME.QSD.

In most cases, you never need to know the distinction between the files in the set, but the knowledge may come in handy someday. For example, if you happen to stumble onto the Quicken directory, knowing about the set of HOME files keeps you from panicking when you see all the multiple copies of the HOME file. Or, on a more serious note, if you use a third-party backup utility, you need to know that all of these files contain data that should be backed up.