Base Points?

I apologize if this has been covered fully in the past. I've just returned to the game after a hiatus.

I also tried to do some research in the boards and in the community, and I haven't been able to land upon any clear description of what the goal of Base Points is? It's clearly a different leveling scheme, but do we have "Mastery" tier rewards? Can we see those somewhere? What's the purpose and goal of this system?

Thank you!