Difference between Windows SharePoint Services (WSS) and Microsoft Office SharePoint Server 2007 (MOSS)

What is the difference between Windows SharePoint Services (WSS) and Microsoft Office SharePoint Server 2007 (MOSS)
It is important that you know the difference between Windows SharePoint Services (WSS) and Microsoft Office SharePoint Server 2007 (MOSS). While WSS and MOSS are both pieces of software built by the Microsoft Office team, WSS is included as a part of the Windows Server 2003 operating system while MOSS is a separate product with its own SKU. You should think of WSS as the underlying platform and think of MOSS as a value-added set of components and services that has been built on top of this platform.
WSS does not have its own licensing model. Instead, the use of WSS is controlled through Windows Server 2003 licenses. This makes it very cost effective for companies to roll out applications that have been designed and built on top of the WSS platform. MOSS, on the other hand, has its own licensing model that includes server-side licenses and client access licenses (CALs). The MOSS licensing model is further broken out into a Standard Edition and an Enterprise Edition