This is a certain module of Python that contains constants related to Win32 programming. It is not part of the Python 2.6 release, but should be part of the download of the pywin32 project, that gives access to most of Microsoft Windows Win32 API. This gives a developer the ability to create and use COM objects, and the Pythonwin environment, in Python programming.
The guide to variables provided in win2com module can be found here: https://www.programcreek.com/python/index/475/win32con