Facets define characteristics and requirements for J2EE projects. When you add a facet to a project, that project is configured to perform a certain task, fulfill certain requirements, or have certain characteristics.
If you selected Faces Project as the configuration when creating your dynamic Web project, the correct facets have already been added to your project. If you created a Web project without selecting that configuration, you need to add the correct facets to the project so that it supports Faces:
WS-I refers Web service interoperability; this includes interoperability across platforms, operating systems, and programming languages. The WS-I organization sets out standards collected in documents called Profiles that define the requirements needed to make a Web service interoperable. The Rational Developer products validate Web services against the WS-I Simple SOAP Binding Profile 1.0 (WS-I SSBP) and the WS-I Attachments Profile 1.0 (WS-I AP). For more information on WS-I, refer to their Web site: http://www.ws-i.org/