OWL Services (OWL-S), formerly known as DAML-S, is part of the Semantic Web Services effort. OWL-S provides an ontology that allows for the automatic discovery and composition of services. OWL-S accomplishes this goal by incorporating a service profile, process model, and grounding, written in OWL.
OWL-S is a W3C member submission that unites many concepts from both Web Services and the Semantic Web. W3C keeps a listing of its relations to many existing technologies of both these areas. %red% <insert something that uses OWL-S >
DAML-S is the precursor to OWL-S, and the two languages share many similarities.