How does godot’s 3d renderer work

I would like to make a 3d game in the Godot game engine. I was wondering if and how the Godot engine optimizes 3d scenes. For example some games unload chunks that the player isn’t looking at while other games (I believe) make texture quality worse the farther away you get. This would be nice to know if Godot automates any of this so that I can work with what is already built into Godot to optimize my game more.