In the install path of Git for Windows, what's the difference between ./git-bash.exe and bin/bash.exe and bin/sh.exe?

git-bashis part of "Git for windows" and provides a command line environment similar to *nix bash.

Windows 10 includes "Windows subsystem" which could provide a Linux environment inside Windows (which includes sh and bash, a short comparison can be found at Difference between sh and bash)

You can use any of them for git. It may be an advantage to use the same as your co-workers (if you would need any help with the shell or a script).