I am trying to make progress in Unity on understanding how aspect ratios and resolution work. I can't quite wrap my head around the topic. For example, I am trying to make a simple breakout style game, but in order to do that, I need to consider the world units and how each brick would fit into the scene. From what I have read, world units are dependent on screen resolution and aspect ratio. How would I be able to make something like this if mobile games are played on different devices (and ones with notches nonetheless). Also I'd like to know how to achieve this without using the tacky black bars that some games use.
Any information regarding this would be extremely appreciated.