Part of the car's lighting setup, the tail light inner on the driver's side, is an important safety feature of the car enabling other road users to clearly see the vehicle from the rear.
The tail light inner driverside is an external light that fixes to the outside of the car at the rear on the driver's side and is contained in either a metal or plastic housing. The tail lights can be in the same housing as other lighting such as the indicator lights, brake lights, parking lights, reverse lights and hazard lights, forming one single tail light with several functions. When indicating to go left, the indicator or signal light bulbs flash to indicate to other road users that the driver intends to turn left. The indicator light is also used by drivers in emergency situations to alert other road users that there is a potential hazard. Brake lights illuminate when the driver applies pressure to the brakes to let other road users know that the car is slowing down or stopping. Reverse lights illuminate when the driver puts the car into reverse, indicating to other road users that the car is reversing. Parking lights and hazard lights are used when the car is pulled up on the roadside, to alert other road users to the fact that there is a parked car. On some cars the tail light is a separate unit, however, often clustered together with the other rear vehicle lights. The tail light is wired up to come on when the front side lights are on and emits a red light which is designed to be duller than the brake light, so that the brake light is distinguishable from the tail light.
Unfortunately, because of where it's positioned on the vehicle and the fragile nature of the bulbs, the tail light inner driverside is prone to being smashed and cracked, particularly in a crash but also as a result of stones and debris flying up from the road or badly maneuvered reversing.
When replacing the inner rear tail light on the driver's side it's important that you purchase a tail light intended for the driver's side of the car. Rear tail lights come in many different sizes and styles. Purchasing a new tail light inner driverside will ensure you get a quality part that fits the make and model of your car.