Android is an open source operating system used in Android mobile devices. It is based on the Linux kernel and allows developers to write managed code using Java-like languages. The Android platform was announced in 2007 with the founding of the Open Handset Alliance, a consortium devoted to advancing open standards for mobile devices. When released in 2008, most of the Android platform was made available under the Apache free-software license. The document discusses Android's architecture, features, application development process, and compares it to other mobile operating systems like iOS and Windows Phone OS.