Since files and folders are both listed in the file tables, however, there are attributes by which you can distinguish one from the other. But an extension is not one of them. Folders do not have an actual size (they calculate the size of everything assigned to that folder instead), and they do not have an extension.
Herein, what is Windows folder extension?
The FOLDER file type is primarily associated with Explorer by Microsoft Corporation. The . FOLDER extension is an entry in the registry that allows Explorer to create a new folder with the characteristics defined by entries in the registry key HKEY_CLASSES_ROOT. Folder and all related keys.
Likewise, how many file extensions are there? In an 8.3 file format, you have 3 locations that may be used by alphanumeric characters to create a 3 character long extension. Using 0-9 and A-Z, you come up with a possible total of 26 letters plus 10 numerical values that are interchangeable. As such, there are 36 possible characters for each of the 3 positions.
Beside this, how do I enable folder extensions?
1] Through Folder Options Open Control Panel > Appearance and Personalization. Now, click on Folder Options or File Explorer Option, as it is now called > View tab. In this tab, under Advanced Settings, you will see the option Hide extensions for known file types. Uncheck this option and click on Apply and OK.
How do I change the file type of a folder?
If you want to quickly change folder type, you can right-click the folder and choose Properties. Keyboard shortcut for this is Alt+Enter. Open the Customize tab and choose a template from Use this folder type as a template (Windows XP and Vista) or Optimize this folder for (Windows 7, 8, 8.1 and 10).