The Unified Foundational Ontology (UFO) is a foundational ontology that provides a structured, philosophically grounded framework for conceptual modeling, knowledge representation, and semantic interoperability.

It integrates insights from formal ontology, philosophy of language, cognitive science, and linguistics, and is organized into three main parts:

1) UFO-A (dealing with endurants, events, qualities, and their relationships, based on a formal theory of objects and universals),

2) UFO-B (a foundational ontology of events and processes),

3) UFO-C (covering social entities such as agents, roles, norms, and institutions).

By offering a coherent set of categories and relations, UFO supports the analysis, design, and evaluation of conceptual models across domains, promoting clarity, reusability, and ontological consistency.