More specifically, the implementation of the Connection interface is provided by the JDBC driver.
JDBC uses the Dependency Injection pattern so that your code doesn't need to depend on the JDBC driver implementation.
The soul is dyed the color of its thoughts. Think only on those things that are in line with your principles and can bear the light of day. The content of your character is your choice. Day by day, what you do is who you become. Your integrity is your destiny - it is the light that guides your way. - Heraclitus