Need explanations for each of the available variants of bootloaders

This might not be the best channel for reporting this issue, but I can't think of a better one. I'm using the MatrixPortal S3 merely as an example here, but the same need applies to any target.

I'm running into some issues flashing an Adafruit board I have. One of the things I have to do is install a UF2 bootloader. The problem is, the official bootloader download page (https://circuitpython.org/board/adafruit_matrixportal_s3/) offers a zip file for the bootloader firmware with seven different files. The instructions on the page say to install `combined.bin`.

* What are all the other files? The learning page references `tinyuf2_combo.bin`. How is this different from `combined.bin`?
* When flashing with `esptool.py`, should I flash `.uf2` or `.bin` files?
* What's the precise relationship between the Bootloader and CircuitPython itself?

Even if this information can't be robustly summarized on the specific download page, a link to the GitHub repo that generates the binaries would be helpful, and perhaps that repo could have comprehensive explanations of all the build artifacts.

As it is, you have to read dozens of pages on different sites to hopefully glean a partial understanding.

bootloader.bin
combined.bin
ota_data_initial.bin
partition-table.bin
partitions-8MB.csv
tinyuf2.bin
update-tinyuf2.uf2