In other words, a queue is an infinitely large, sequentially maintained collection of data pieces. The size of the Queue determines how many data components can be securely stored and how quickly they can be accessed. When all of the storage sites are filled with data elements, a queue is said to be full. An overflow happens when a new element is added to a full queue. The removal of any data element from an empty queue is not possible and results in an underflow. Such a queue is referred to as an empty queue.