In-game training content and modules created by the Refrag Community for all to use, if any of the content isnt behaving properly, make sure to reach out to the Creator of the content!
Remember: If you want to load up any Refrag mode, make sure you use the Play Now button on the top-right of your dashboard!

The Creator Studio section of the Community Hub are mostly aiming-related modes created and shared by the community.
With Creator Studio you can play community-made sets, as well as older versions of Refrag training modes. For example, you can load up older versions of Prefire, if you want to.
It's worth noting that Refrag can't guarantee the quality of any sets created by community members (though we're sure they're great!).
If you want to try your hand at creating your own set, a good place to start is the Creator Studio page on this wiki, which can be found here.
The Grenade Groups section of the Community Hub are groups of grenades that the community have created and shared for everyone to use.
NADR Strategies are recordings of strategies that you can watch back inside of the game, simply click the Play button on any of them.
VPL Playlist stands for Versus Play List which is a mode where you and your teammates practice holding the bombsite versus full executes community used by Professional Teams.