For Android Smart Phone, Wear & TV, separate images are required which are also available for downloading. System Image: To create an AVD( Android Virtual Device) for any specific API, you should download a System Image as per your system type (either 32-bit or 64-bit OS).Hence, whenever you want to download packages for any new Android version like 8.0 or 7.0, always select and download SDK Platform for it. To compile your Application against specific version, to load specific widgets, views and tools for compilation, is done by SDK Platform. SDK Platform: Android SDK platform contains packages/libraries to develop & build Android Application for specific versions.So lets see which packages do we have to install onto our machine: In the previous image, you can see some packages of API level 22 that we have installed on our system, and there is also Update available for it. You can easily understand which API Level/Android Version you want to install, as there is a list with Android version names listed, you just have to select one and click on OK. For specific API level (version) of Android, you have to download additional packages from the section SDK Platforms.SDK Tools and Build-tools contain packages to build your Android Application and several updates/patches from Google for better Application Development.It requires internet connection to download the packages (most are of large size) so make sure you have one. From here, you can check the required Build tools, SDK Tools, Platform Tools, SDK Platforms, Samples for SDK, System Images (for AVD), Documentations, Sources for Android SDK and Extra Packages for your development. It will also list all the new items & Updates available for already installed items for your system. Launch your SDK Manager, and you'll get to see the list of currently installed items. But if that does not happen, you can open the SDK Manager by going to Tools → Android → SDK Manager or click on the icon in the Android Studio toolbar.

Generally when you launch the Android Studiofor the first time, it will open the Android SDK Manager window, to prompt you to install the required packages for android development. The Android SDK Manager, manages various Android SDK versions, tools and various other useful packages that you can select and download, to keep your development environment up-to-date. Now in this tutorial we'll shed some light on the Android SDK manager, how it is important for Android Application Development and what packages you require to download to start with android app development. In the previous tutorial, we talked about the required tools for Android Application Development and also listed out steps to configure those tools onto our Computer.

Android SDK Manager & required Packages.

Android sdk tools download