Filmic vs Filmic Log

[Morgosis]

Hi! i recently saw a video by Blender Guru about achieving realism in the render, he talked about an external download that it was filmic log, i think since 2.8 blender has the filmic by default and while i was looking at it i saw that in the view tab under the color management it has filmic and filmic log, but i dont quite understand the difference, which one is better and why? or when to use one above the other? sorry for my english, thanks a lot!