The document summarizes the Onto-DIY workshop paper on semantics in Onto-DIY. It discusses how Onto-DIY allows both technical and non-technical users to semantically define concepts, rules, and services. It also describes how semantics are represented in ontologies, semantic decision tables, and user-centric services in the Onto-DIY environment. Finally, it outlines future work such as automatic mapping between the different semantic divisions and social, context-aware service creation tools.