Players are one of FreeStyle’s fundamental building blocks. A player has a lot of control over its music, from how it sounds to how it is displayed in the notation view. Since it would be tedious to set up all this information each time you create a new player FreeStyle gives you a powerful short-cut: The Player Library. The player library stores commonly used “Forms” or “Templates” that you can use to create Players from.
You can think of a Player Template as a “Rubber Stamp” for creating Players. Extending the metaphor, if you modify a rubber stamp, it does not affect “prints” that have already been made with it, only the ones it will make in the future. If you modify a print, it does not change the stamp, or any other prints. Player Templates work the same way. Changing a Player Template does not affect Players that have already been made, only ones that you make from that point forward. Similarly, modifying a Player, either in the Ensemble window, or in the “Edit Player Info” dialog does not affect the Player Template it was created from, or Players in other documents.
To summarize, a Player Template is a “stamp” that you can use to create a Player from. After the Player is created it is no longer tied to the Template that created it in any way.