Properties are expressed through predicates, which can be singular terms or nominalized predicates. Properties can be referred to by singular terms like "being honest" or "Mary's favorite property". Properties can have both argument and attributed roles in propositions and facts
Conceptualization is an abstract view of selected world parts with objects and relationships. Explicit specification of conceptualization is called ontology. Conceptualization is language-independent, while ontology is language-dependent
Reality encompasses all existing things in the universe, including both physical and conceptual entities. Philosophical questions about reality are addressed in ontology, which is a branch of metaphysics. Reality can be defined as the totality of all things, structures, and events, observable or not
Existence is the state of having being or reality, contrasting with nonexistence. Essence refers to an entity's essential qualities, while existence indicates its existence. Ontology studies the nature and types of existence
Hole is an opening in or through a medium, usually solid body. Can be natural or artificial, intentional or unintentional. Smallest observable holes are pinholes, largest are black holes. Deepest hole on Earth is Kola Superdeep Borehole at 12 kilometers
OWL is a semantic markup language for publishing ontologies on the Web. Document serves as reference guide for OWL users. OWL documents consist of optional headers and axioms about individuals