Does JVM creates thread if there is no thread created explicitly ?

When JVM starts, it itself creates threads even there is no explicit thread created by program :

  1. Main thread - for running main() method

  2. Garbage collection

  3. Finalization

Apart from JVM itself, different APIs and Framework creates threads for different purposes.

Examples

 1. AWT / Swing : for event handling
 2. Timer : for scheduling task execution

 3. RMI : for calling remote object

 4. Web servers : for managing multiple requests