Do you understand exactly what the compiler is, and what the JVM is?
The compiler translates your Java source code into bytecode (instructions that the computer understands). The compiler checks if your source is valid Java code.
The JVM (Java Virtual Machine) is what executes the compiled bytecode when you run your Java program.
The page
About the Java Technology from Sun's Java Tutorials explains it in pictures.
Please
use a meaningful subject line (instead of "need help") when you post a question on JavaRanch.
[ September 12, 2008: Message edited by: Jesper Young ]