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 ...

While the launch services in OS X use file name extensions to associate files with various applications, generally users do not need to interact with these extensions and the system keeps them hidden ...

The default setting for Windows is to not display a file's extension, which is the last period in a file name followed by 2 or 3 letters. Therefore, when viewing files in Windows you would only see ...