Data sources in Nexus PRIME provide the connection to the data stored in internal tables in PRIME or any external source, such as LDAP, JDBC, SCIM or CSV files. In order to access the data sources, data pools are needed. Data pools are abstract representations of the data including lists of fields and their data types. The core templates are are an interpretation of the data pools. They are used for defining the core objects in PRIME, for example, cards, persons and so on.