What is Android SDK?

The Android SDK is the software development kit for the Android operating system. It includes a runtime, emulator, tools and documentation to help developers create applications for Android devices. These SDK tools are often used to develop mobile apps for Android phones and tablets. Developers use this toolkit to create apps that can be distributed through Google Play or other serving systems such as Amazon Appstore and BlackBerry World. The first set of open source SDK code was released in December 2009 while the latest release was on November 16th 2012.