Door pockets refer to small, horizontal compartments located on either side of a vehicle's interior door panels. These pockets are designed to provide storage space for various items such as pens, sunglasses, water bottles or other small personal belongings that the driver and passengers may need while on the go. The term "door pocket" is commonly used in reference to cars, trucks, vans, and SUVs, but can also be found in some buses and trains as well.