I try to understand the practical difference between using different quality values when writing to PNG.

Does it simply affect image size, and generally (though, as I discovered, there are some exceptions), the larger number you use, up to 100, the smaller the file size is?

Also, what does it really happens if you use -quality 0? Does it mean this will be the same as not using -quality?

I already read https://imagemagick.org/script/command-line-options.php#quality, of course, but I wasn’t able to understand much from there.