DS_STORE files are commonly found on machines running Mac OS operating system.
The DS_Store (Desktop Services Store) are files that contain system customization information, such as icons, type of wallpaper, font, columns, screensavers.
This type of file is created automatically by the MacOS file manager called Finder.
The equivalent to DS_Store files on Windows are the Thumbs.db or desktop.ini files.
The main functionality of these files is to store metadata of the different files and folders.
DS_store files are not designed to be opened by the user and therefore do not have a specific program associated with them.
Their binary content is encoded to be used directly by the Mac OS operating system, so they are not readable with a text editing applications.
For more general information about files, file extensions and registry you can read one of the following articles:
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