And we can assume it’s not a city bus, because it says school bus.

That’s such an american thing to say. School and city buses are the same thing in a lot of the world. Sometimes they are chartered by the school with public funds, sometimes they are just normal bus lines that have additional timeslots before and after school.

And even school uses itself vary a lot by each countrie. The US has these yellow monsters while a lot of Asian countries use small vans as buses.