file association

(1) The relationship of one file to another based on the data it contains.

(2) An established relationship between a file and the application used to open it. There are default file associations pre-configured in every operating system for all the common file types. However, if a file's icon or name is clicked without a default association, the OS prompts the user for the application to use. File associations can be easily changed (to learn how in Windows, see Win File association).

Associate a File in Windows XP

For Vista and subsequent versions of Windows, use the Default Programs control panel to change associations (see Win File association). In Windows XP, open Explorer and select Tools/Folder Options/File Types and scroll to the file extension. Click Change and select an application.

Associate a File in the Mac

To change a file association in the Mac, click on any file of that type and select Get Info.