A stack is a data structure that is used in programming. 
There are two basic operations that can be performed on 
a stack to modify its contents, which are called PUSH 
and POP. The main difference between PUSH and POP is 
what they do with the stack. PUSH is used when you want 
to add more entries to a stack while POP is used to 
remove entries from it.

Read more: Difference Between PUSH and POP | http://www.differencebetween.net/technology/software-technology/difference-between-push-and-pop/#ixzz6a1tnzHMZ