How do "inner" and "outer" work in this bubble sort code?

Question

I am trying to learn the bubble sort algorithm in a book for C. I can't seem to understand in the code below how int outer and int inner link to which element of the nums array. Like how does inner become nums[0] while outer becomes nums[1] (if I'm correct), then progresses through the loop?

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

int main()
{
    int ctr, inner, outer, didSwap, temp;
    int nums[10];
    time_t t;

    srand(time(&t));

    for (ctr = 0; ctr < 10; ctr++)
    {
        nums[ctr] = (rand() % 99) + 1;
    }

    puts("\n Here is the list before the sort: ");
    for (ctr = 0; ctr < 10; ctr++)
    {
        printf("%i\n", nums[ctr]);
    }

    for (outer = 0; outer < 9; outer++)
    {
        didSwap = 0;
        for (inner = outer; inner < 10; inner++)
        {
            if (nums[inner] < nums[outer])
            {
                temp = nums[inner];
                nums[inner] = nums[outer];
                nums[outer] = temp;
                didSwap = 1;
            }
        }
        if (didSwap == 0)
        {
            break;
        }
    }

    puts("\n Here is the list after the sort: ");
    for ( ctr = 0; ctr < 10; ctr++)
    {
        printf("%i\n", nums[ctr]);
    }

    return 0;
}

Answer 1

inner never becomes nums[0]. inner and outer are array indexes, so when inner is 0, nums[inner] is nums[0].

The code that performs the comparison and swapping never does that with inner and outer, it uses nums[inner] and nums[outer].

        if (nums[inner] < nums[outer])
        {
            temp = nums[inner];
            nums[inner] = nums[outer];
            nums[outer] = temp;
            didSwap = 1;
        }