ART replaces Dalvik as the runtime environment in Android. Both use the same application packaging format, which contains Dalvik bytecode. ART pre-compiles it.
Dalvik bytecode (DEX) was designed to efficiently interpreted. Eventually, Dalvik added a JIT compiler suitable for battery powered platforms. What ART stops short of is replacing Dalvik bytecode, perhaps with a more efficient intermediate representation for the purposes of pre-compiling.
Dalvik bytecode (DEX) was designed to efficiently interpreted. Eventually, Dalvik added a JIT compiler suitable for battery powered platforms. What ART stops short of is replacing Dalvik bytecode, perhaps with a more efficient intermediate representation for the purposes of pre-compiling.