Insertion sort
Think about the sequence of numbers in the picture below. It starts with a small number (written as ≤x), then a big number (≥x) and then a medium sized number (written as x). If this had specific numbers, it might start with 2 (small), 10 (big), 4 (medium). The number 10 is bigger than the number 4. So if the sequence were in order from smallest to biggest, it should start with 2, 4, 10. So the second and third numbers should be swapped. So, in the example below, the sequence should start with ≤x, x, ≥x.