The module is built-in to the python interpreter.
>>> import builtins
<module 'builtins' (built-in)>
>>> import sys
<module 'sys' (built-in)>
Such modules are represented with (built-in) as you can see in the above interactive session.
If the module is loaded from a file, it will be represented as follow:
>>> import ftplib
<module 'ftplib' from 'C:\\Python34\\lib\\ftplib.py'>