Linux has a symlink named /bin/sh that points to /bin/bash

It's worth pointing out that the shell will behave differently depending on whether it is called as sh or bash, so the fact that /bin/sh and /bin/bash are the same file does not mean they behave the same when they are executed, they share a lot of code (both being bourne shells) which is why they were made into the same file but bash enhancements won't work from /bin/sh.