This week's book giveaways are in the Refactoring and Agile forums. We're giving away four copies each of Re-engineering Legacy Software and Docker in Action and have the authors on-line! See this thread and this one for details.
jvm is Java virtual machine. It interprets the bytecode and executes your program.
jre is Java runtime environment It is the jvm and Sun's standard Java class libraries and anything else needed to execute existing Java programs but not enough to create or change programs. Compare to sdk=system develpment kit