When do you use Windows SharePoint Services?
WSS is used for team and project web sites or portals. It provides the base capabilities of creating and managing portals. You can create many top level portals and each can have multiple sub-portals. For a smaller organization this could be a top level portal per department and then sub-portals for each project. For example a portal for Engineering with a sub-portal for the current and upcoming release and a portal for Professional Services with sub-portals for each ongoing customer implementation. On each portal you can place web parts (more later on) to show contact lists, event calendars, announcements, document libraries and more. You can use these portals to share information within your department, projects or meetings. WSS makes it very easy to create new portals and to manage them. User rights are used to determine what a user is allowed to do. Users can get notified about events like a document has been added, a contact has been changed, etc. These notifications can be sent real time when the event happens or via a daily or weekly summary of all events. WSS does not provide any search capabilities if it uses MSDE 2000 as its data store. When using MS SQL Server 2000 it can search within one portal. But it does not allow to search cross many portals including sub-portals. So you can only search for all the information within the portal you are in.
When do you use SharePoint Portal Server?
SPS builds on top of WSS so by default it provides all the capabilities WSS provides. The most compelling reasons why to use SharePoint Portal Server 2003 instead of WSS is it improved search capabilities, ability to target content to different audiences and integration capabilities. SSP enables you to import users from Active Directory or any other LDAP data source on a one time or scheduled basis. Audiences are used to target content to specific groups of users. When importing users from an external data source you specify which user property is mapped to the SharePoint audience which gives you ultimate control over how to target content, whether this is the department, location or any other property. SSP provides a "My Site" site which is a personal portal for each user. This site provides a private and public document library, manage all alerts and links, etc. Any link or alert the user sets up on any portal are shown on the "My Site" portal. SSP allows to search across all existing portals which provides a very powerful search. Through search scopes you can also define the areas or topics which should be included in a search. The user can select the search scope when performing a search. SSP Single-Sign-On capability allows to map portal credentials to credentials of other enterprise applications so that SSP can retrieve information from these enterprise applications without requiring an additional authentication by the user. Microsoft BizTalk Server can be used for integrations between SharePoint Portal Server and other enterprise applications. SSP also allows to create server farms to scale over multiple servers and ultimately achieve the scale required for large organizations with thousands of portals.