The difference between queue and stack

queue ： Every window in line to buy tickets is a queue , The newcomers stood at the back , The earlier you come, the more forward , First come first serve , Referred to as “ fifo ” principle . therefore A queue is a first in, first out data structure .

Stack ： For example, pile up books , One by one, from bottom to top , But you can only take books from the top , At last （ above ） The first to take , Put first （ below ） Take the last . therefore Stack is an advanced and backward data structure .