ODBC refers to Open Database Connection. ODBC is an SQL-based Application Programming Interface (API) created to enable Windows applications to use SQL for database access. Essentially ODBC is a gateway for Windows software to access and retrieve data from databases that are located elsewhere.
ODBC connection is done by first installing an ODBC connector or driver (downloadable from the internet). And then specifying within the driver the exact database location and access credential for connecting to the database. Multiple ODBC connections can be set up at the same time of course, it’s just that one connection (or DSN) is needed per different database. After the setup, users can use the ODBC connection to issue SQL commands to the database from the Windows application and or retrieve the corresponding data directly into the Java application.
ODBC connection is often mentioned with or compared to JDBC connection. The two are very similar in setup and usage, it’s just that JDBC is created by Sun Microsystems for Java applications and ODBC is created by Microsoft for Windows software applications. Depending on the application, one of JDBC or ODBC is needed.