<P> The order in which elements come off a stack gives rise to its alternative name , LIFO ( last in , first out ) . Additionally , a peek operation may give access to the top without modifying the stack . The name `` stack '' for this type of structure comes from the analogy to a set of physical items stacked on top of each other , which makes it easy to take an item off the top of the stack , while getting to an item deeper in the stack may require taking off multiple other items first . </P>
when items are to be retrieved in reverse order from which they were stored we use
a stack