There are different kinds of dirt, it turns out:
Topsoil is the very top layer of dirt. It has lots of organic matter in it, from the plants and dead bugs and such lying on the surface. This makes it nutrient-rich. Topsoil is also called black dirt because the organic matter makes it darker. It often has some clay in it, so it will be “sticky.”
Fill dirt is from the next layer down. It has no organic matter in it – plant roots don’t grow that deep, and bugs don’t dig that deep. Fill dirt is lighter in color than topsoil, and because there’s no organic matter to break down, it’s more stable; it will settle less over time.
Screened dirt is fill dirt that’s been fed through a screen to make it finer and more granular by breaking down the chunks (a screening machine is pictured). Screened dirt is easier to contour, and it will settle even less than fill dirt which hasn’t been screened.
Notably, “potting soil” is not dirt. It’s mostly peat moss and pine bark. It’s often mixed with fertilizer and is designed to retain moisture.