Each Linux command returns an exit code, with 0 indicating success and non-zero values indicating failure. You can use the $? variable to access the exit code and control program flow in scripts.

The exit code 126, for example, means that an issued command could not be executed. If you use this same code to indicate an unusual condition in a script, a calling script might just assume that ...

Yes, that’s the exit code and it’s meant to indicate that the pwd command you just used ran without any errors. An exit code of 0 always indicates that no problems were encountered.