Most files on your computer are known as data files. A data file does not contain any instructions for opening it. Instead, data files require a specific program to interpret the information contained in them. For instance, a Word document requires a word processor to open it. Each type of data file on your device is associated with a specific executable file, and when you try to open a data file, your device opens that associated program. You can also open a data file directly from its associated program. If there is no program associated with a file type, your device will not be able to open it. Executable files, on the other hand, do not require any other program to run, since they contain specific instructions for your machine to execute.