Android and Java

In Java, you write your Java source file, compile it into a Java byte code using the Java
compiler, and then run this byte code on the Java VM. In Android, things are different.
You still write the Java source file, and you still compile it to Java byte code using the
same Java compiler. But at that point, you recompile it once again using the Dalvik
compiler to Dalvik byte code. It is this Dalvik byte code that is then executed on the
Dalvik VM. Figure illustrates this comparison between standard Java (on the left)
in Android using Dalvik (on the right).