An ontology constructor is a tool or system that is used to build ontologies, which are formal representations of a set of concepts within a domain, and the relationships between those concepts. Ontologies are often used in the field of artificial intelligence and knowledge representation, as they provide a way to define and organize domain knowledge in a machine-readable form Some common features of Schemantra ontology constructor includes: A graphical user interface for creating entities Support for ontology in JSON-LD format schema generator for defining types, properties, and their relationships Schemantra is useful for building and maintaining large, complex ontologies, as they provide a way to organize and visualize the relationships between concepts in an intuitive way