ART
Android runtime (ART) is the managed runtime used by applications and some system services on Android. ART and its predecessor Dalvik were originally created specifically for the Android project.
ART and Dalvik are compatible runtimes running Dex bytecode, so apps developed for Dalvik should work when running with ART.
Dalvik
Dalvik Virtual Machine or DVM is a Register-Based virtual machine that was designed and written by Dan Bornstein. The Dalvik virtual machine was named by Bornstein after the fishing village “Dalvík” in Eyjafjörður, Iceland, where some of his ancestors used to live. Dalvik is a discontinued virtual machine (VM) in the Android OS that executes applications written for Android.
Dalvik bytecode format is still used as a distribution format, but no longer at runtime in newer Android versions.
Android itself is a Linux system with Dalvik sitting on top of it. DVM takes android apps, turns them from java code into bytecode that the Linux system can run.
Difference Between DVM and ART
| DALVIK VIRTUAL MACHINE | ANDROID RUN TIME |
| Faster Booting time | Rebooting is significantly longer |
| Cache builds up overtime | The cache is built during the first boot |
| Occupies less space due to JIT | Consumes a lot of storage space internally due to AOT |
| Works best for small storage devices | Works best for Large storage devices |
| Stable and tested virtual machine | Experimental and new – not much app support comparatively |
| Longer app loading time | Extremely Faster and smoother Faster and app loading time and lower processor usage |
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