停 is the general verb for 'to stop' (a car, rain, an action) and 'to park' a vehicle. It's broader than 停止 (tíng zhǐ), which means 'to cease/stop' an ongoing activity or process (e.g., production, service), and more common than 止 (zhǐ), which is formal and often used in set phrases or warnings. For parking specifically, 停 is the everyday word; 停放 (tíng fàng) is more formal and emphasizes where you leave the vehicle.