Which one should I download JRE or JDK?
JRE enables you to run java applications
JDK enables you develop java applications
“What Java Do I Need?” You must have a copy of theJRE (Java Runtime Environment) on your system to runJava applications and applets. To develop Java applications and applets, you need the JDK (Java Development Kit), which includes the JRE.
http://www.oracle.com/technetwork/java/javase/downloads/index.html