> For the complete documentation index, see [llms.txt](https://help.santesuite.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.santesuite.org/santedb/data-and-information-architecture/conceptual-data-model/entities/class-codes.md).

# Class Codes

Entities are further classified by their class code and determiner code. The determiner code of an entity is responsible from differentiating a type of an entity (i.e. antigen, dose number, material type, etc.) and an instance or series of instances of an entity (an actual vial of vaccine, a box of syringes, etc.). Most entities within the SanteDB system are expected to be stored as instances of entities, classes of entities will primarily be restricted to materials whereby a class of antigens (OPV for example) will have both instances (vials of OPV) and sub-classes of representing dose numbers (OPV0 – OPV3). Provides a summary of the entity classes and how they are classified in the data model.

| **Entity Class**      | **Class Code** | **Description**                                                                                                                      |
| --------------------- | -------------- | ------------------------------------------------------------------------------------------------------------------------------------ |
| Entity                | ENT            | An entity is the base class used to represent a person/place/thing in the SanteDB data model.                                        |
| Material              | MAT            | A material represents a physical thing to which participates in the delivery of care. For example: a syringe, a box of vaccine, etc. |
| Manufactured Material | MMAT           | A manufactured material represents a material which is manufactured such as diluent, vaccine, syringes, etc.                         |
| Place                 | PLC            | A place represents a physical location where health services are provided.                                                           |
| Organization          | ORG            | An organization represents an administrative structure which employs providers, operates clinics, etc.                               |
| Person                | PSN            | A person represents a human being.                                                                                                   |
| Patient               | PAT            | Represents a person who receives health services.                                                                                    |
| Provider              | PVD            | Represents a person who provides health services.                                                                                    |
| User                  | USR            | Represents a person who actively uses the system.                                                                                    |
| Device                | DEV            | Represents a physical object on which health services data is entered, stored, etc.                                                  |
| Application           | APP            | Represents a piece of software which is used to access, record or update medical data.                                               |