Unlike Dalvik, which since Android 2.2 "Froyo" uses just-in-time (JIT) compilation to compile the bytecode every time an application is launched, ART introduces use of ahead-of-time (AOT) compilation by performing it upon the installation of an application. By reducing the overall amount of compilation that needs to be performed across the operation of an application, a mobile device's processor usage is reduced and battery runtime is improved. At the same time, ART brings improvements in performance, garbage collection, applications debugging and profiling.