Self-service is the style of food service in which customers go to a counter or display where food is laid out and help themselves, especially to cold items. Salad bars, buffets, cafeterias, and supermarket delis all run on the principle: the customer chooses, portions, and often pays by weight or item. It cuts labour costs and gives diners control, but it shifts food safety responsibility onto display management: hot foods must be held hot, cold foods cold, serving utensils provided and changed, and sneeze guards fitted. Time limits apply, since food on display deteriorates, and leftovers from the bar must be discarded, never recycled. Done well it is efficient and popular; done badly it is a contamination risk.