McDonald's is the world's largest fast food chain serving 68 million customers daily. It began in 1940 as a barbecue restaurant operated by Richard and Maurice McDonald in the US. Businessman Ray Kroc joined in 1955 and purchased the company, overseeing its worldwide growth. McDonald's emphasizes developing menus customers want through research. It introduces new products and removes old ones to meet changing tastes. McDonald's locations are spread widely for convenience and accessibility.