Imagine you are sitting in the drivers seat facing forward. The passenger side of the vehicle is on your right side and the drivers side is on your left. With the “Windshield” directly in front and the “Back Glass” directly behind the driver. The drivers seat is considered to be the front of the vehicle. Anything behind the driver is the rear of the vehicle. As an example; The passenger side back door glass is broken. We would identify that part location as the “right rear door”. In most cases a glass part located on either side of the vehicle and is not in a door is called a “Quarter Glass”. While a generally smaller a piece of glass located in a door is called a “Vent Glass”. Although in most modern cars and trucks the “Vent Glass” is stationary and does not open or close. These smaller windows were used in older vehicles to provide fresh air to passengers, and the name is still used today.