Definition: File extensions, for any computer files, are the three letters at the end of the filename. These three letters are preceded by a dot, to separate the filename from the extension. In the example
mypresentation.ppt the file extension is
ppt.
The file extension indicates to your computer, to which program this file belongs. When you double click on the filename, the computer recognizes which program this file belongs to, opens that program and finally opens the file. In the example above, the computer would recognize that this file was created with PowerPoint, because the file extension, .ppt is the extension associated with PowerPoint.
Also Known As: extension
Examples: When Mary double clicked on the filename
mypresentation.ppt the computer recognized that this file extension is associated with the program PowerPoint, and opened the presentation in PowerPoint.
See also