Higraphs are generalizatins of Euler/Venn diagrams that are used for information system representation. Due to their ability to represent collections of sets together with structural relationship between them, they seem to be ideal for ontology representation. This talk will discuss higraph definition and will contrast higraph ability for system representation with graphs and hypergraphs. We will illustrate higraph use in Computer Science with such examples as: conceptual specification of databases, semantic networks, security constraints in OS. We will also show the relationship between EA sketches and higraphs.