Sometimes a component can serve as a constituent of multiple composite objects. For example, XML schema "ABC" might contain schema "XYZ" as one of its components. Other services and/or schemas might also include schema XYZ as a component. Components that can belong to more than one composite object are referred to as shared components. Components that can only belong to a particular instance of a composite object are referred to as nonshared components. For example, the operations, bindings and interfaces associated with a Web service are considered nonshared components. These objects belong solely to the service and cannot function as constituents of other composite objects. Schemas, however, are considered sharable, meaning that they do not belong exclusively to a particular composite object.