A simple overview follows... For more detailed information refer to the Health Information Models index on the openEHR wiki.
What is an Archetype?
The Concise Oxford Dictionary defines an archetype as "an original model, prototype or typical specimen". In openEHR, an archetype is the model (or pattern) for the capture of clinical information - a machine readable specification of how to store patient data using the openEHR Reference Model.
Archetypes are a keystone of the openEHR architecture. Each archetype describes a complete clinical knowledge concept such as 'diagnosis' or 'test result'. By design, they provide structure and specify content which means that archetypes can be both clinically meaningful and interpretable by EHR systems. Archetyped data will have the same meaning no matter what context it is used within the EHR and, similarly, no matter which EHR system it is used or what language is used.
...