Describe queue?

Ans:  It is a type of data structure in which the data are stored in and retrieved on a First in first out (FIFO) basis. It grows in the direction of increasing addresses in the memory. New data are added at the back of the queue (High-address end) and retrieved from the front (low-address end) of the queue.

Illustrate difference between Stack and Queue?

STACK: One end of stack is remain fixed ( the bottom) whereas the other end rises and falls as data are popped  and pushed Single Pointer is required to point to the top of the stack

QUEUE: Both of the ends of a queue move to higher addresses .2 pointers are required to keep track of the two ends of the queue.