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Concept - represents a “meaning” in a terminology that has a code, one or more names, one or more semantic types, (optional) text definitions, and (optional) key/value attributes.
Atom - represents a single “name” from a terminology for a given code. All of the “atoms” in a concept are considered synonymous with each other. The naming convention “atom” comes from the UMLS (https://umls.nlm.nih.gov)
Definition - represents a textual definition for a concept.
ConceptRelationship - represents a relationship between two Concepts with a general type (such as “parent”, “child”, “broader”, or “narrower”) and a specific type (such as “has_finding_site”).
ConceptTreePosition - represents one position of a Concept in it’s hierarchy (as computed by transitive closure of the parent/child relationships). In mono-hierarchy terminologies (such as ICD10CM), concepts will have only a single tree position. However, in poly-hierarchy terminologies (such as SNOMEDCT), concepts may have multiple tree positions.
Mapset - represents a collection of mappings from one terminology to another one.
Mapping - represents a mapping from an individual code to code in a different terminology (e.g. SNOMED → ICD10)
Metadata - Used to provide additional information about metadata fields spread throughout the model (e.g. semantic types, relationship types, attribute names, atom term types, etc.)
Subset - In other contexts called a ValueSet or a Refset, this represents a collection of codes within a terminology that represent a portion of the content used for a particular reason. For example, you could create a “primary cancer diagnoses” subset of SNOMED that would represent exactly those concepts that could be legitimately used to label a primary cancer diagnosis.
Terminology - represents a terminology and associated information.
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