I had a college professor who would said "Nothing is pure and few things are simple."
OTOH, I could be wrong. After all, I am using logic.
I mentally sort driving lights into spot, flood and fog lights.
When a light is mounted low, cresting a hill for instance, there is a blind spot just over the top. When I was in high school and determined to be a good driver, when I was on high beam, I would dip them to low beam and back up as I went over, just to be sure. Off-roaders put their driving lights above their sight-line, on the roll bar. WWII blackout light were on top of the fenders.
To evaluate them find a blank light-colored wall in a parking lot. Drive up to it and back away with the fog lights on. You should see a line that drops as you back away. That's how you aim Hella H-4 headlights, instead of a machine that sits on the posts on sealed-beam headlights. Hella brand headlights (not the American quartz-halogens) have such a sharp cut-off that, when you hit a bump, you can see the line move forward and then back on the ground in front of you. I hardly need fog lights.