File attributes are references to a file or folder on the computer's filestore. When giving one a value it will be the full pathname of the file, though this value would normally be determined using a file system browser.
File attributes are runnable; where the actual type has an obvious method of running, such as an audio or video file then JEAN will carry out that action. Otherwise the system Internet browser will be called and the action will be the same as if the file had been opened from the browser's menu. This will depend on the file's MIME type, for example on a Windows machine a MS Word document would be opened in Word.
In addition to being runnable, file attributes can have one or more applications defined for them. These can be called from the menu. A typical example would be an editor.