What's the point of Physical and Magic Damage Types

[Faafetai]

I am pretty positive Titan's punches contrary to what you would assume, is not physical, but he has magical punches because he is magical. At least thats what dark mind tells me in the fly text. I might just be getting lucky dodges or something every time, but I swore this was a thing when I was messing around in titan extreme.

I would like for a way to know what the attacks would be. Figuring them out it fun, but some are a bit strange.