Windows SharePoint Services v3.0 && Microsoft Office SharePoint Server 2007
when you starting developing sharepoint application you will found your self ask this question what is the deference between Windows SharePoint Services v3.0 and Microsoft Office SharePoint Server 2007?
MOSS is a superset of WSS, MOSS takes the foundation laid by WSS v3.0 and expands upon it
Think of WSS as the content management brain, which powers the functionality of both products. MOSS represents the body, which uses that brain power to move its arms and legs, creating additional functionality and mobility. Both services allow you to share information, collaborate with other users and develop webpages. Additionally, MOSS offers a way to aggregate your WSS services into internet/intranet portals that can be targeted toward different users, groups, or organizations.
you can get details about MOSS and WSS from this links:
Windows SharePoint Services v3.0 vs Microsoft Office SharePoint Server 2007