Java???

Hello Guys, I am new to Java, and I want to know:
1, what is JDK(Java Development Kit)
2, What is J2sdk

are JDK and J2SDK the same thing.

I want to start programming in Java, what do i need.
Do i Need to have JVM(Java Virtual Machine Also) also.
Regards Harbir

I could write a lengthy response, but Sun's already got it all covered with their New2Java section:
http://java.sun.com/learning/new2java/index.html

Thanx Buddy that was a big help, i appreciate it.