title: Why not use heap sort always
body: <p>The <strong>Heap Sort</strong> sorting algorithm seems to have a worst case complexity of O(nlogn), and uses O(1) space for the sorting operation.</p>
  
  <p>This seems better than most sorting algorithms. Then, why wouldn't one use Heap Sort always as a sorting algorithm (and why do folks use sorting mechanisms like Merge sort or Quick sort)?</p>
  
  <p>Also, I have seen people use the term 'instability' with Heap sort. What does that imply?</p>