Android powers millions of mobile devices around the world. It is the largest installed base of any mobile platform and growing fast also. Android development is mostly done in Java as it is not a difficult language to learn, but how it applies to Android development can be confusing without a firm foundation in the language. Android Java is not exactly standard Java, but learning standard Java will make it much easier for you to pick up Android development.
What is Android? Android is a software stack for mobile devices that includes an operating system, middleware and key applications. The Android SDK provides the tools and APIs necessary to develop applications on the Android platform using the Java programming language.
What is Open Handset Alliance?The Open Handset Alliance is a group of 84 technology and mobile companies who have come together to accelerate innovation in mobile and offer consumers a richer, less expensive, and better mobile experience.