A convertible or sedan is a type of automobile. An AUTO is a four-letter word for a vehicle, and CAR is a three-letter word for the same. A convertible or sedan is a type of CAR that has either a retractable roof or a fixed roof, respectively. Convertibles are typically two-door vehicles, while sedans are usually four-door vehicles. Both types of cars are popular choices for those looking for a reliable and stylish mode of transportation.