In OSLC, each artifact in the lifecycle is an HTTP resource that has a URI as its name and can be manipulated with HTTP methods, such as GET, PUT, or POST. Every artifact or resource has an RDF representation that consists of a subject, a predicate, and an object. For example, if you were to link from a requirement to a test case, the RDF representation would have the requirement as its subject, the type of relationship or link type as its predicate and the test case as its object, each identified by a URI.