Queue is a FIFO data structure. FIFO stands for First In First Out. It means the element added first will be removed first from the queue. A real world example of Queue is a line for buying tickets at a station. The person entering first in the Queue is served first.

Stack is a LIFO data structure. LIFO stands for Last In First Out. The element that is added last is removed first from the collection. In a Stack elements are added or removed from the top of stack.

A real world example of Stack is back button in browser. We can go back one by one only and it works in the reverse order of adding webpages to history.