WSS is included as a part of the Windows Server 2003 whereas MOSS is a separate product.
WSS doesn’t have its own licensing model, it is controlled through Windows Server licenses whereas MOSS has it own licensing model that includes both Server-Side as well as client accesses licenses.
WSS provides the underlying platform on which MOSS is built on. MOSS includes all the features of WSS and adds its own set of components as services.
Additional features that are part of MOSS includes
Social networking web parts – Colleague Web Part, Colleague Tracking Web Part, In Common Web Part etc.
MySite, RSS, Site Directory, User Profile, Audience Targeting,
Enterprise content sources– Files shares, Web sites, SharePoint sites, Exchange Public Folders, and Lotus Notes databases, more relevant results, people search, business data search.
Enterprise content management, Forms-driven business processes, Business intelligence.
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