A stock car is a railroad
car used to transport livestock
. Stock cars are similar in appearance to boxcars
but have slats on the sides, allowing free circulation of air so that the animals
A stock car is also a type of race car, based on a production model and usually driven on a circle track, although these days they don't share much but the names with any vehicles you might see on the street. NASCAR is the governing body for this type of auto racing.