What is the purpose of a motor vehicle inspection sticker?

The purpose of a motor vehicle inspection sticker is to provide visual proof that a vehicle has passed a required safety and/or emissions inspection. This demonstrates that the vehicle, at the time of inspection, met minimum safety and/or environmental standards set by the relevant governing authority (state, province, etc.). The sticker serves as a readily visible confirmation for law enforcement to quickly determine if a vehicle is legally allowed to operate on public roads.