The platform tools are typically updated every time you install a new SDK platform. Each update of the platform tools is backward compatible with older platforms. Usually, you directly use only one of the platform tools—the Android Debug Bridge (adb). Android Debug Bridge is a versatile tool that lets you manage the state of an emulator instance or Android-powered device. You can also use it to install an Android application (.apk) file on a device.
The other platform tools, such as aidl, aapt, dexdump, and dx, are typically called by the Android build tools or Android Development Tools (ADT), so you rarely need to invoke these tools directly. As a general rule, you should rely on the build tools or the ADT plugin to call them as needed.
Note: The Android SDK provides additional shell tools that can be accessed through adb, such as bmgr and logcat.
A shell tool you can use to interact with the Backup Manager on Android devices supporting API Level 8 or greater.
Provides a mechanism for collecting and viewing system debug output.