Association
Updated: 11/16/2019 by Computer Hope
An association or file association describes installed software associated with a particular file extension or file format. For example, a file with a .TXT extension is associated with Notepad or WordPad in the Microsoft Windows operating system by default. When opening a file (double-clicking the file), the default associated program opens the file. If no program is associated with the file, you're asked to choose what program should be used.