Android

           

            Android is a mobile operating system (OS) based on the Linux kernel and currently developed by Google. With a user interface based on direct manipulation, Android is designed primarily for touchscreen mobile devices such as smartphones and tablet computers, with specialized user interfaces for televisions (Android TV), cars (Android Auto), and wrist watches (Android Wear).

The OS uses touch inputs that loosely correspond to real-world actions, like swiping, tapping, pinching, and reverse pinching to manipulate on-screen objects, and a virtual keyboard. Despite being primarily designed for touchscreen input, it also has been used in game consoles, digital cameras, regular PCs (e.g. the HP Slate 21) and other electronics.

What is Android?

                      It is an open-sourced operating system that is used primarily on mobile devices, such as cell phones and tablets. It is a Linux kernel-based system that’s been equipped with rich components that allows developers to create and run apps that can perform both basic and advanced functions.

                 Android versions have been developed under a confectionery-themed code name and released in alphabetical order; the exceptions are versions 1.0 and 1.1, as they were not released under specific code names:

                  

                        Alpha (1.0) - Beta (1.1) - Cupcake (1.5) - Donut (1.6) - Eclair (2.0–2.1) - Froyo (2.2–2.2.3) - Gingerbread (2.3–2.3.7) - Honeycomb (3.0–3.2.6) - Ice Cream Sandwich (4.0–4.0.4) - Jelly Bean (4.1–4.3.1) - KitKat (4.4–4.4.4) - Lollipop (5.0–5.0.2)

             Android apps are written in the Java programming language. The Android SDK tools compile your code—along with any data and resource files—into an APK: an Android package, which is an archive file with an .apk suffix. One APK file contains all the contents of an Android app and is the file that Android-powered devices use to install the app.

 Following is the list of software's you will need before you start your Android application programming.

• Java JDK5 or JDK6
• Android SDK
• Eclipse IDE for Java Developers (optional)
• Android Development Tools (ADT) Eclipse Plugin (optional)

Before you start writing your first example using Android SDK, you have to make sure that you have setup your Android development environment.