A school bus is any type of bus owned, leased, contracted to, or operated by a school or school district. The school bus can be seen in many places from a school to a parking lot. It is regularly used to transport students to and from school or school-related activities, but not including a charter bus or transit bus. Various configurations of school buses are used worldwide; the most iconic examples are the yellow school buses of the United States and Canada which are also found in other parts of the world.
In North America, school buses are purpose-built vehicles distinguished from other types of buses by design characteristics mandated by federal and state/province regulations. In addition to their distinct paint color (school bus yellow), school buses are fitted with exterior warning lights (to give them traffic priority) and multiple safety devices. (Wikipedia)