A journal may refer to any of the following:
1. A journal is a location of stored activities or events occurring on a computer or network. A journal helps to determine what may have caused an issue or a device to go down without having to monitor a device yourself.
2. When referring to a file system, a Journaling File System (JFS) is a method of keeping track of how the data is manipulated on the hard drive. Each time a request is made to the hard drive, an entry is first made in the journal. The JFS allows the computer to check the last few journal entries for errors instead of having to check all the files on the drive.
For example, Windows 98 running FAT32 is not a journaling file system, and this is why the system must run ScanDisk if the computer is improperly turned off. However, Windows XP running NTFS and later versions of Windows with NTFS, which is a journaling file system, does not need to run ScanDisk, it checks the journal.