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 ...

When you double-click on a file in Windows XP, the operating system will automatically open the file using a program that has been is associated with the file's extension. It is possible, though, to ...