Rational Developer for System z
PL/I for Windows, Version 8.0, Programming Guide

ODBC Driver Manager

When you use the ODBC interface, your application makes calls through a Driver Manager. The Driver Manager dynamically loads the necessary driver for the database server to which the application connects. The driver, in turn, accepts the call, sends the SQL to the specified data source (database), and returns any result.

Rational Developer for System z
PL/I for Windows, Version 8.0, Programming Guide