How on earth does Radix MSD sort work?


I’ve tried looking at explanations on YouTube and many different forums, but I am VERY new to the work of sorting algorithms and cannot wrap my head around the bug words they’re using. I understand how algorithms like Quicksort and Insertion sort work, but I just cannot wrap my brain around Radix MSD and other Radix variants.

In: 2

Start by taking a group of numbers less than 10,000. All of these numbers will be represented by 4 digits. Divide the numbers into groups by the first digit; so 0’s go in the first group, 1’s go in the second group,etc. Next, within each group, divide the numbers into subgroups by their second digit. Then third, then fourth. Put these groups back together in order, and you have a sorted list.

Radix in this case means the digits; but it could also mean letters, or any other representational piece of the thing to be sorted.