Lesson 0.1
Pixels: what you are painting with
Procreate paints with pixels, a fixed grid of coloured squares. Zoom in far enough and every stroke breaks into blocks.
Raster (Procreate)
Great for textures, soft blends and painterly looks. Can't be enlarged without going soft.
Vector (Illustrator, Affinity)
Made of maths, so it stays sharp at any size. Best for logos. Many pros letter in Procreate, then trace to vector.