why is priority queue much better used with heap? code example

Example 1: priority queue min heap

#include 
using namespace std;
 
// User defined class, Point
class Point
{
   int x;
   int y;
public:
   Point(int _x, int _y)
   {
      x = _x;
      y = _y;
   }
   int getX() const { return x; }
   int getY() const { return y; }
};
 
// To compare two points
class myComparator
{
public:
    int operator() (const Point& p1, const Point& p2)
    {
        return p1.getX() > p2.getX();
    }
};
 
// Driver code
int main ()
{
    // Creates a Min heap of points (order by x coordinate)
    priority_queue , myComparator > pq;
 
    // Insert points into the min heap
    pq.push(Point(10, 2));
    pq.push(Point(2, 1));
    pq.push(Point(1, 5));
 
    // One by one extract items from min heap
    while (pq.empty() == false)
    {
        Point p = pq.top();
        cout << "(" << p.getX() << ", " << p.getY() << ")";
        cout << endl;
        pq.pop();
    }
 
    return 0;
}

Example 2: create a min heap in java using priority queue

int arr[]={1,2,1,3,3,5,7};
        PriorityQueue a=new PriorityQueue<>();
        for(int i:arr){
            a.add(i);
        }
        while(!a.isEmpty())
            System.out.println(a.poll());

Example 3: Difference between Priority Queue and Heap

This website provides a really clear explanation. http://pages.cs.wisc.edu/~vernon/cs367/notes/11.PRIORITY-Q.html

In short, a priority queue can be implemented using many of the data structures that we've already studied (an array, a linked list, or a binary search tree). However, those data structures do not provide the most efficient operations. To make all of the operations very efficient, we'll use a new data structure called a heap.

Example 4: Priority Queue using Min Heap in c++

#include 
using namespace std;
 

int main ()
{
   
    priority_queue  pq;
    pq.push(5);
    pq.push(1);
    pq.push(10);
    pq.push(30);
    pq.push(20);
 
   
    while (pq.empty() == false)
    {
        cout << pq.top() << " ";
        pq.pop();
    }
 
    return 0;
}