Railroad cars are vehicles designed for transporting goods and passengers on railroads. They are typically connected to a locomotive, which provides the power to move the train. There are various types of railroad cars, including freight cars for cargo, passenger cars for travelers, and tank cars for liquids. Each type of railroad car serves a specific purpose. For example, boxcars are used for transporting general freight, while flatcars carry heavy machinery or large items. The design and construction of these cars ensure they can safely carry their loads over long distances on tracks.