I'm really curious about the difference between vector and raster graphics ~ as to when we use one over the other, and how the two can be combined like in the short called Paperman (2012) where they merged 2d and 3d styles of animation for a more authentic and handmade feel overall

What can a pixel be represented by if not a square?

Maybe a time slice from the sweep of an electron gun? (i.e. in old CRT displays)