Android Development Tools

Android SDK:

The Android SDK (software development kit) is a set of development tools used to develop applications for Android platform. 

The Android SDK includes the following:

• Required libraries
• Debugger
• An emulator
• Relevant documentation for the Android application program interfaces (APIs)
• Sample source code
• Tutorials for the Android OS

Every time Google releases a new version of Android, a corresponding SDK is also released. To be able to write programs with the latest features, developers must download and install each version’s SDK for the particular phone. 

Android debug bridge (adb):

Android Debug Bridge (adb) is a versatile command line tool that lets you communicate with an emulator instance or connected Android-powered device.

What ADB do's:

Phone rooting: This is the basic and most common function which in fact is compulsory for Android developers willing to root Nexus or any other Android device.

App side loading: If you want to install an application that’s either not available on Google Play in your location or was removed from the store (like Flappy Bird), then ADB comes handy again. The adb install command will install an APK file onto your Android device, on the condition that you have enabled installation of applications from unknown sources in settings.

Files Push and Pull between a PC and an Android device: Adb push and adb pull, let you easily transfer files between your PC and Android device. Again, this is more helpful when you’re working with rooted devices, since you can achieve the same end using Windows File Explorer

Even more handy commands:  A lot of functions like flashing ROMs to your phone require you to boot into recovery mode. Normally, this requires you to hold down a particular set of buttons on your phone for a certain length of time, which is obnoxious. With ADB, you can install a ROM stored on the computer (helpful if running low on external sd memory). This even gives the command to flash a recovery image which has been topic for those with an unlocked boot loader that have been receiving the unlocked boot loader error message on reboot.

Dalvik Virtual Machine (DVM):

A virtual machine optimized for mobile devices that was designed and written by Dan Bornstein and other Google engineers. Dalvik is a part of the software stack that makes up the Android platform.

According to Google's Android documentation, the Dalvik VM is an interpreter-only virtual machine that executes files in the Dalvik Executable (.dex) format, a format that is optimized for efficient storage and memory-mappable execution. The virtual machine is register-based, and it can run classes compiled by a Java language compiler that have been transformed into its native format.

Android RunTime (ART):

Android Runtime (ART) is an application runtime environment used by the Android mobile operating system. ART replaces Dalvik, which is the process virtual machine originally used by Android, and performs transformation of the application's bytecode into native instructions that are later executed by the device's runtime environment.

DDMS:

DDMS stands for Dalvik debug monitor server, that provide many services on the device. The service could include message formation,call spoofing , capturing screenshot , exploring internal threads and file systems e.t.c.