i am real confused with the two terms namely JVM and JRE....

if some one could help me with the process of how and the order of
execution of jre.exe.. and few question like can we have different
run time environmnents for different applications or there are only
one!!!

where can we see or check the java run rime envirionment and if
possible JVM.... and the exact order of sequence when we execute
the application with the java interpretor or the web application.