Questions tagged [Android] should focus on security of the operating system itself, or of Android-specific apps. Questions about Android that are not directly security-related should be asked at android.stackexchange.com.
Android is an operating system for mobile devices such as smartphones and tablet computers. It is developed by the Open Handset Alliance led by Google. For general information about Android, see wikipedia/Android
The open source nature of Android gives the security community a unique view into the security of one of the world's most popular operating systems.
At its core, Android runs a modified Linux kernel, and thus shares many fundamental security frameworks with the Linux OS. On top that, Android greatly extends the security model of Linux and has many security features that are unique to that platform.
In addition, Android comes bundled with lots of pre-configured software to give a great out-of-the-box user experience. Most of these 3rd party components are also open source, and many Android vulnerabilities are the result of vulnerabilities discovered in 3rd party components rather than in the Android OS itself.