In computer science, a heap is a specialized tree-based data structure that satisfies the heap property described below.
In a min heap, if P is a parent node of C, then the
key (the value) of P is less than or equal to the
key of C.
In a max heap, the key of P is greater than or equal
to the key of C
The node at the "top" of the heap with no parents is called the root node.