What is the role of fast …

A fast food restaurant, also known as a quick service restaurant (QSR) within the industry, is a specific type of restaurant that serves fast food cuisine and has minimal table service. The food served in fast food restaurants is typically part of a "meat-sweet diet", offered from a limited menu, cooked in bulk in advance and kept hot, finished and packaged to order, and usually available for take away, though seating may be provided. Fast food restaurants are typically part of a restaurant chain or franchise operation that provides standardized ingredients and/or partially prepared foods and supplies to each restaurant through controlled supply channels. The term "fast food" was recognized in a dictionary by Merriam–Webster in 1951.

Arguably, the first fast food restaurants originated in the United States with White Castle in 1921. Today, American-founded fast food chains such as McDonald's (est. 1940) and KFC (est. 1952) are multinational corporations with outlets across the globe.