What is a bak file?
A bak file, or a .bak file, is a file with a .bak extension that indicates that it is a backup file, or often a duplicate of another file, that is stored in a safe location for backup and restore. This common format is used by many different types of software systems, including word processing and office software, design software applications, and more.
A .bak file can be used in many different contexts. In some cases, they are part of an automatic save function for software that ports these temporary files to a safe location if the system encounters unexpected difficulties. These files can also be created manually where users go in and make changes to the file extension. Alternatively, a system can periodically archive large quantities of .bak files for general backup purposes.
While using .bak files can be an effective backup system, there are some storage strategy concerns. The creation of .bak files can lead to 'hard disk drive bloat' where many duplicate files take up too much space. Another problem with .bak files is that, unlike many original files, users cannot immediately determine what type of file a file is. There's a reason the three-digit file extensions are unique to each individual file format. Sometimes backup strategies make these files too generic and make it extremely difficult to determine whether the file is, for example, a document, video, executable, or some other type of format.