Why does sh -version on my mac output the version of a bash shell?

I see sh -version GNU bash, version 3.2.57(1)-release (arm64-apple-darwin24) Copyright (C) 2007 Free Software Foundation, Inc. yet in https://developer.apple.com/library/archive/documentation/OpenSource/Conceptual/ShellScripting/shell_scripts/shell_scripts.html it mentions that /bin/sh is the Bourne Shell: *The first thing you should notice is that the script starts with ‘#!’. This is known as an interpreter line. If you don’t specify an interpreter line, the default is usually the Bourne shell (/bin/sh). However, it is best to specify this line anyway for consistency.* I know in Linux /bin/sh points to the default shell, which defaults to Bash. but the apple script link is saying something else.