What is the difference between a gloss and matt iPhone case?

What's the difference between the two?
Is one hard or soft?
Is one rubber and plastic etc?

The Matt is usually soft and it feels rubberized. It feels like a rubber band.

A gloss is a smoother plastic hard feel. Gloss is usually a hard case with a plastic smooth touch.

Gloss and matt are the finishes like paint one is shiny one is dull

Gloss and matte is just shiny or not shiny, it has nothing to do with the materials used, or density.

Gloss is normally shiny and matt is dull just like in a paint