Of the top of my head: You choose what car to buy, but the bus company chooses what us to buy. You maintain your own car but the bus company maintains the bus.

Of the top of my head: You choose what car to buy, but the bus company chooses what us to buy. You maintain your own car but the bus company maintains the bus. You drive your own car, but a professional hired and vetted by the bus company drives the bus. You drive your car from a to b when you want, but the bus travels along predefined routes at specific times.