What is the difference between chinos and slacks?
Fantastic question, Rhett. It's mostly the material and the dressy-ness. Slacks are commonly made of wool and cut like "suit pants." Chinos are more commonly made of cotton. If it has pleats, its probably slacks. If its flat-front, that's generally chinos. There's no hard and fast lines of delineation, but generally if it's dressier, you call them slacks, and if its more casual, its chinos.
I use the sneakers and a t-shirt test. If you would look out of place with societal norms wearing the pants with sneakers and a t-shirt, its slacks. If you would see public university students wearing the pants with sneakers and a t-shirt, they're chinos (although probably called "khakis" for some reason.)