What to go for ?? JDK or JRE

Well if net speed is not an issure, I suggest go for the lastest version of JDK from

http://java.sun.com/javase/downloads/index.jsp

most probably its

JDK 6 Update xx

whats the difference between JDK and JRE !!

As the name says JDK is java development KIt, it bundles many softwares like (debuggers, development tools, ) along with one or more JREs. On the other hand JRE is the run time environment, its the implementation of Java Virtual Machine meant for running JAVA programs...

If all you want to do is to learn java basics at minimal level (to just run javac mycode.java and then run it) i would suggest go for JRE only...