MySQL Connector/ODBC Developer Guide
Before you connect to a MySQL database using the Connector/ODBC driver, you configure an ODBC Data Source Name (DSN). The DSN associates the various configuration parameters required to communicate with a database to a specific name. You use the DSN in an application to communicate with the database, rather than specifying individual parameters within the application itself. DSN information can be user-specific, system-specific, or provided in a special file. ODBC data source names are configured in different ways, depending on your platform and ODBC driver.