What are the -Xms and -Xmx parameters when starting JVM?

Question

Please explain the use of Xms and Xmx parameters in JVMs. What are the default values for them?

Answer 1

The question itself has already been addressed above. Just adding part of the default values.

As per http://docs.oracle.com/cd/E13150_01/jrockit_jvm/jrockit/jrdocs/refman/optionX.html

The default value of Xmx will depend on platform and amount of memory available in the system.