Definition
In the simplest terms, a Data Type is the constraint on a data element. It defines the type of data held within the data element. For example, the data element Date of birth is associated with the data type xs:date, which only allows for the input of data in the YYYY-MM-DD format.
The definitions, including rules and constraints for valid values for all Data Types are defined using the following metamodel:
Name: the name of the data type
Description: a description of the data type, if applicable
Type
Simple - e.g. varchar, string, integer
Enumerated - a list of possible values
Reference
Relationships: to other data types or data element
Examples
