How Do Artists Create the Illusion of Depth on Flat Surfaces?

Artists use tricks to make flat pictures look like they have depth. Imagine you're looking at a picture of a road that goes off into the distance. The artist draws the lines of the road so they come together in the far part, just like when you look down a hallway, it seems to get smaller as it goes away. That’s one trick! Artists also use colors: things that are farther away might be lighter or bluer, and closer objects are darker or more vivid. This makes everything seem to pop out of the paper like it's real.