The Simple answer to this question is JRE is the super-set of JVM.
That is, the code which is compiled with java compiler(javac) produces the byte-code(.class files). jre which is the subset of jdk contains the required libraries along with jvm. jvm runs the byte-code and produces machine code that is in the machine readable form with the support of libraries required for that code.
To see the configuration of jvm go to :
C:\Program Files\Java\jre7\lib\i386\jvm.cfg
This file contains the List of JVMs that can be used as an option to java, javac, etc.
