In computer science, a priority queue is an abstract data type

which is like a regular queue or stack data structure, but where

additionally each element has a "priority" associated with it.

In a priority queue, an element with high priority is served before

an element with low priority. If two elements have the same

priority, they are served according to their order in the queue.

While priority queues are often implemented with heaps, they are

conceptually distinct from heaps. A priority queue is an abstract

concept like "a list" or "a map"; just as a list can be implemented

with a linked list or an array, a priority queue can be implemented

with a heap or a variety of other methods such as an unordered

array.

[Wikipedia](https://en.wikipedia.org/wiki/Priority_queue)