Introduction to Android

How Android started



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. It's is built on a Linux foundation. Google purchased the initial development of the software, Android Inc., in 2005. The unveiling of the Android distribution on November 5, 2007 was announced with the founding of the Open Handset Alliance, a consortium of 84 hardware, software, and telecommunication companies devoted to advancing open standards for mobile devices.

This alliance shares a common goal of fostering innovation on mobile devices and giving consumers a far better user experience than much of what is available on today's mobile platforms. By providing developers a new level of openness that enables them to work more collaboratively, Android will accelerate the pace at which new and compelling mobile services are made available to consumers. Android is often symbolized by the green robot to the right.

Android has evolved rapidly since its launch. Google has named all projects after a dessert. The main releases are listed below, this is nothing you need to memorize, it's just to illustrate the rapid pace of development and all the innovations. Android is developed "on Internet time", that is much faster than the old style of development (for example Windows releases that are typically several years apart).

Release	Date	Main features
1.5 Cupcake	04/2009	3rd party keyboards, Widgets, video recording
1.6 Donut	09/2009	Voice search, text to speech, higher screen resolution, turn by turn navigation
2.0/2.1 Eclair	10/2009, 01/2010	Better sync, Exchange support, camera flash, Bluetooth 2.1, improved Calendar, Browser Support for more screen sizes
2.2 Froyo	05/2010	improved performance, WiFi hotspot, better application launcher, apps on SD card, improved Market and update process.
2.3 Gingerbread	12/2010	improved copy/paste, native VoIP calling, improved input, NFC support, front-facing camera, better power management
3.0, 3.1, 3.2 Honeycomb	02/2011, 05/2011, 07/2011	Tablet-only version, System/Action bars, enhanced multi-tasking, better copy/paste, two-pane Calendar/Gmail/Contacts, Gallery, HW acceleration, multi-core CPU support. USB hosting, joysticks, gamepads, UI refinements, performance improvements, compatibility for non-tablet apps
4.0 Ice Cream Sandwich	10/2011	Support for both phones and tablets, virtual buttons, resizable widgets, easier-to-create folders, customizable launcher, major UI improvements, integrated screenshot capture, better voice integration, face unlock, tabbed browser, synch with Chrome, data usage monitor, built-in photo editor, Android Beam, People app

As you can see there have been around 2 major releases per year. An interesting observation is that all releases have had codenames after desserts in alphabetical order (Cupcake, Donut, Eclair, Froyo and so on). The next Android version after Ice Cream Sandwhich is rumored to be called "Jelly Bean".

Flavors of Android

You saw above that the Android releases have been named after various desserts. So it's only natural that there are several flavors of Android! The Android platform is made available under developer-friendly open-source licenses, that gives device manufacturers and mobile operators significant freedom and flexibility to design products. That flexibility also means there are several different "flavors" of Android. The biggest device manufacturers often put their own "skin" on top of Android, which means the User Interface on a phone or tablet from one manufacturer may be different than the UI from another. Here are some examples:

Cust_ID	Cust_Name
"Vanilla"	Nexus One, Nexus S, Galaxy Nexus
TouchWiz	Samsung
Sense	HTC
Blur/Motoblur	Motorola
UX	Sony Ericsson

"Vanilla" interface means it's an unmodified version of Google's Android. The Nexus series (HTC made the Nexus One, Samsung made the Nexus S and Galaxy Nexus) use this version, so if you get a Nexus phone you'll get updates faster than for other phones that use some of the heavier modifications. Some manufacturers, for example Huawei, ZTE, Acer and LG have done some light additions to Android, often in the form of additional apps. Arguably HTC's Sense is the version that has the largest additions to the basic Android system.

If it's important for you to get timely updates then you may want to search some of the many Android Forums and check the manufacturer's track-record.

The following are examples of the home screens for the "vanilla" Android 2.3 and 4.0 as well as the most common "skins", TouchWiz and Sense. As you can see, TouchWiz and Sense have put a lot of content on their home screens, the "vanilla" versions are more plain and leave it to you to add apps, widgets and shortcuts to your home screen. From Android 3.0 the navigation buttons are actually part of the screen.

This variety and flexibility is certainly part of Android's strength, you're not just staring with a static icon set. Even the wallpaper in Android can be live! But this makes it more challenging to make a guide like this. So we'll mostly stick to the "vanilla" layout when the operations are explained.

Here is an example of the home screen for an Android tablet (Asus Transformer):



Technical details



If you're not too interested in the technical details, you can skip this section. Google released most of the Android code under the Apache License, a free software license.[14] The Android Open Source Project (AOSP) is tasked with the maintenance and further development of Android. Android consists of a kernel based on the Linux kernel, with middleware, libraries and APIs written in C and application software running on an application framework which includes Java-compatible libraries based on Apache Harmony. Android uses the Dalvik virtual machine with just-in-time compilation to run compiled Java code. Android has a large community of developers writing applications ("apps") that extend the functionality of the devices. Developers write primarily in a customized version of Java. There are currently more than 520,000 apps available for Android. Apps can be downloaded from third-party sites or through online stores such as Android Market, the app store run by Google.