A sports prototype, sometimes referred to simply as a prototype, is a type of race car that is used in the highest-level categories of sports car racing. This is basically a purpose-built sports racing car, as opposed to the street-legal and production-based ones, and is therefore not intended for consumer purchase or production beyond that required to compete in races.
Prototype racing cars have competed in sports car racing since before World War II, but became the top echelon of sports cars in the 1960s as they began to replace homologated sports cars. Current ACO regulations allow most sports car series to use two forms of cars: grand tourers (GT), which are strictly based on street cars, and prototypes, which are allowed a great amount of flexibility within set rule parameters.
In historic racing, they are often called "sports racing cars". Sometimes, they are metonymically referred to as "Le Mans cars", as the 24 Hours of Le Mans has been closely associated with the category in recent decades and features entries from several of the main championships contested by prototypes.[1][2][3]