The document describes the insertion sort algorithm sorting the array [15, 9, 9, 10, 12, 1, 11, 3, 9]. It works by taking each element from the unsorted part of the array and inserting it into the correct position in the sorted part. It iterates through the array, swapping elements if the current element is less than the element preceding it, until the subarray is sorted.

1. Insertion Sort Algorithm
15 9 9 10 12 1 11 3 9
0 1 2 3 4 5 6 7 8
currentStartIndex: 1
innerIndex: 1

2. Insertion Sort Algorithm
15 9 9 10 12 1 11 3 9
0 1 2 3 4 5 6 7 8
currentStartIndex: 1
innerIndex: 1
9 smaller than 15,
so they need to swap

3. Insertion Sort Algorithm
9 15 9 10 12 1 11 3 9
0 1 2 3 4 5 6 7 8
currentStartIndex: 1
innerIndex: 1

4. Insertion Sort Algorithm
9 15 9 10 12 1 11 3 9
0 1 2 3 4 5 6 7 8
currentStartIndex: 1
innerIndex: 0
innerIndex no longer bigger than
zero, inner loop exits

5. Insertion Sort Algorithm
9 15 9 10 12 1 11 3 9
0 1 2 3 4 5 6 7 8
currentStartIndex: 2
innerIndex: 2

6. Insertion Sort Algorithm
9 9 15 10 12 1 11 3 9
0 1 2 3 4 5 6 7 8
currentStartIndex: 2
innerIndex: 2
9 and 15 swapped

7. Insertion Sort Algorithm
9 9 15 10 12 1 11 3 9
0 1 2 3 4 5 6 7 8
currentStartIndex: 2
innerIndex: 1
innerIndex moved left

8. Insertion Sort Algorithm
9 9 15 10 12 1 11 3 9
0 1 2 3 4 5 6 7 8
currentStartIndex: 2
innerIndex: 1
9 is not smaller than 9,
inner loops exits

9. Insertion Sort Algorithm
9 9 15 10 12 1 11 3 9
0 1 2 3 4 5 6 7 8
currentStartIndex: 3
innerIndex: 3

10. Insertion Sort Algorithm
9 9 10 15 12 1 11 3 9
0 1 2 3 4 5 6 7 8
currentStartIndex: 3
innerIndex: 3
10 and 15 swapped

11. Insertion Sort Algorithm
9 9 10 15 12 1 11 3 9
0 1 2 3 4 5 6 7 8
currentStartIndex: 3
innerIndex: 2
10 is not smaller than 9,
inner loops exits

12. Insertion Sort Algorithm
9 9 10 15 12 1 11 3 9
0 1 2 3 4 5 6 7 8
currentStartIndex: 4
innerIndex: 4

13. Insertion Sort Algorithm
9 9 10 12 15 1 11 3 9
0 1 2 3 4 5 6 7 8
currentStartIndex: 4
innerIndex: 4
12 and 15 swap

14. Insertion Sort Algorithm
9 9 10 12 15 1 11 3 9
0 1 2 3 4 5 6 7 8
currentStartIndex: 4
innerIndex: 3
12 is not smaller than 10,
inner loops exits

15. Insertion Sort Algorithm
9 9 10 12 15 1 11 3 9
0 1 2 3 4 5 6 7 8
currentStartIndex: 5
innerIndex: 5

16. Insertion Sort Algorithm
9 9 10 12 1 15 11 3 9
0 1 2 3 4 5 6 7 8
currentStartIndex: 5
innerIndex: 5
1 and 15 swap

17. Insertion Sort Algorithm
9 9 10 12 1 15 11 3 9
0 1 2 3 4 5 6 7 8
currentStartIndex: 5
innerIndex: 4

18. Insertion Sort Algorithm
9 9 10 1 12 15 11 3 9
0 1 2 3 4 5 6 7 8
currentStartIndex: 5
innerIndex: 4
1 and 12 swap

19. Insertion Sort Algorithm
9 9 10 1 12 15 11 3 9
0 1 2 3 4 5 6 7 8
currentStartIndex: 5
innerIndex: 3
…etc…