What is pixel art?
Pixel art is 2D graphics made without any filters or brushes, just the pen tool and the bucket. It is still in use today in modern games.
Pixel art is a good way to learn about old computer and console limits, about optimizing colors and creating re-usable and tiling graphics.
It is also pissible to combine pixel art with 3D graphics to create games, images and visualizations with a "retro" feel.