Autotrader.com is an online marketplace for buying and selling new, used, and certified vehicles. It offers a wide range of cars, trucks, SUVs, and vans. Users can search for vehicles based on various criteria such as price, make, model, and location. The platform also provides tools and resources for car buyers, including expert reviews, car news, and buying tips. Additionally, Autotrader.com features options for selling cars, allowing users to place ads and get instant cash offers. The site aims to make the car buying and selling process convenient and efficient for its users.