McDonald's is an American hamburger and fast food restaurant chain. It was founded in 1940 as a barbecue restaurant operated by Richard and Maurice McDonald, in San Bernardino, California. In 1948, they reorganized their business as a hamburger stand, using production line principles. The first McDonald's franchise using the arches logo opened in Phoenix, Arizona in 1953. Businessman Ray Kroc joined the company as a franchise agent in 1955 and subsequently purchased the chain from the McDonald brothers. Based in Oak Brook, Illinois, McDonald's confirmed plans to move its global headquarters to Chicago by early 2018.Today, McDonald's is one of the world's largest restaurant chains, serving approximately 69 million customers daily in over 100 countries across approximately 36,900 outlets as of 2016. McDonald's primarily sells hamburgers, cheeseburgers, chicken products, french fries, breakfast items, soft drinks, milkshakes, wraps, and desserts. In response to changing consumer tastes and after facing criticism for the unhealthy nature of their food, the company has expanded its menu to include salads, fish, smoothies, and fruit. A McDonald's restaurant is operated by either a franchisee, an affiliate, or the corporation itself. The McDonald's Corporation revenues come from the rent, royalties, and fees paid by the franchisees, as well as sales in company-operated restaurants. According to a BBC report published in 2012, McDonald's is the world's second largest private employer (behind Walmart with 1.9 million employees), 1.5 million of whom work for franchises.