In the macOS environment, system information files, called odbc.ini, are used to store data source information. Two versions of the file, one for storing User DSN information and one for System DSN information, are placed in separate library directories on your machine (See “Configuration Through the System Information File” for locations of the odbc.ini files). The odbc.ini files are plain text files that contain data source definitions. Data source definitions can be created or modified by editing the odbc.ini files using a text editor or the graphical user interface (GUI) provided by the iODBC Administrator. For instructions on configuring data sources through the odbc.ini file, see "Configuration through the System Information (odbc.ini) File". See "Data Source Configuration through a GUI (macOS)" for details on using a GUI.