Android Runtime consists of Dalvik Virtual machine and Core Java libraries.
DVM is optimized for low processing power and low memory environments.
Unlike JVM, the Dalvik Virtual Machine doesn’t run .class files, instead it runs .dex files.
Android 2.2 “Froyo“ brought trace-based just-in-time (JIT) compilation into Dalvik, optimizing the execution of applications and dynamically compiling frequently executed short segments of their bytecode into native machine code.
