Windows is even set up to hide these extensions from you in its default configuration, so you’ll want to turn them on to make things easier for you.
The extension was a 3-letter ‘code’ indicating the type of file.Īfter the introduction of Windows 95, you may have more than 8 characters in a name (up to 256), but the 3-letter extension remains.
In the ‘olden’ days when DOS was the common operating system, all files had a maximum of 8 characters in their name, followed by a period, followed by the extension. Each file type also has a distinct structure so that the program that created it can read it correctly. The difference is the way that the application program recognizes the file. A standard AutoCAD drawing is created as a DWG file. For example, a Corel WordPerfect letter file is created as a WPD file. Every file in a computer is created as a particular type or format.
