Microsoft Office Sharepoint Server (MOSS) is a combination of two previous products, Microsoft SharePoint and Microsoft Content Management System.
It has a large number of features out of the box that are very desirable for any single system, including hosting files with customisable metadata. Page and file publishing that is enabled for end users, excellent search... the list goes on.
Essentially it is designed to enhance and organisations collaboration activities across the entire enterprise, leveraging the organistations existing Office application to create an enterprise system.
