Stacks and queues

Containers

abstract data structure that permits storage and retrieval of data items independent of content
they're distinguished by the retrieval order they support
in stacks and queues this retrieval order depends on the insertion order

Stacks

support retrieval by last-in, first-out (LIFO) order
push - insert item at the top of the stack
pop - return (and remove) the top item of the stack

Queues

support retrieval in first in, first out (FIFO) order
minimize the maximum time spent waiting
(average waiting time will be the same regardless of whether FIFO or LIFO is used)
enqueue - insert an item at the back of the queue
dequeue - return (and remove) the front item from the queue

Both stacks and queues can be effectively implemented using either arrays or linked lists.