It&#x27;s essentially a way to gather more information concerning a file&#x2F;application without needing to fill the overall filesystem with fairly irrelevant data. So it&#x27;s a natural place for things like the third-party fonts a program needs, the data files that a program uses, the settings a program has, etc. For example, a game could have a save file that&#x27;s simply named Blah.sav, but in the data streams, it could have Blah.sav:Save1, Blah.sav:Save2, etc