A file extension, or file name extension, is the letters immediately shown after the last period in a file name. For example, the file extension.txt has an extension of .txt. This extension allows the ...

A file extension is a suffix that is added to the end of a file name after a dot. It is usually two to four letters long. File extensions help Windows and other operating systems to know the standard ...

1How to view file name extensions for all files on a Mac 2How to view file name extensions for a individual file on a Mac The default setting for Mac OS is to not display a file's extension. For those ...