What are fast food, a la carte, in-class and buffet?

Fast food refers to instant consumption, which is reasonable in price, meets the needs of daily life, and has the characteristics of quickness, convenience, standardization and environmental protection.

A la carte restaurant refers to a restaurant that eats at will and pays for itself.

Eating in the dining hall means that you can only consume it in the store, and you can't take it away or take it out.

Self-catering means that consumers choose their own dishes that suit their own tastes, and then eat in restaurants.