Each concept in SNOMED CT is logically defined through its relationships to other concepts. Every active SNOMED CT concept (except the SNOMED CT Concept Root concept) has at least one | is a | relationship to a supertype concept. | Is a | relationships and defining attribute relationships are known as the defining characteristics of SNOMED CT concepts. They are considered defining because they are used to logically represent a concept by establishing its relationships with other concepts. This is accomplished by establishing | Is a | relationships with one or more defining concepts (called supertypes) and modeling the difference with those supertypes through defining attributes.
This tab is used for editing relationships, either supertype-subtype reltionships relationships and attribute relationships. See Editing new relationships for further information on relationships edition.