What is Android?
- Android is an open source and Linux-based Operating System for mobile devices such as smartphones and tablet computers. Android was developed by the Open Handset Alliance, led by Google, and other companies.
- Android offers a unified approach to application development for mobile devices which means developers need only develop for Android, and their applications should be able to run on different devices powered by Android.
- The first beta version of the Android Software Development Kit (SDK) was released by Google in 2007 whereas the first commercial version, Android 1.0, was released in September 2008.
- On June 27, 2012, at the Google I/O conference, Google announced the next Android version, 4.1 Jelly Bean.
- Jelly Bean is an incremental update, with the primary aim of improving the user interface, both in terms of functionality and performance.
Why Android ?
Features of Android
Android is a powerful operating system competing with Apple 4GS and supports great features. Few of them are listed below −
| Sr.No. | Feature & Description |
| 1 | Beautiful UIAndroid OS basic screen provides a beautiful and intuitive user interface. |
| 2 | ConnectivityGSM/EDGE, IDEN, CDMA, EV-DO, UMTS, Bluetooth, Wi-Fi, LTE, NFC and WiMAX. |
| 3 | StorageSQLite, a lightweight relational database, is used for data storage purposes. |
| 4 | Media supportH.263, H.264, MPEG-4 SP, AMR, AMR-WB, AAC, HE-AAC, AAC 5.1, MP3, MIDI, Ogg Vorbis, WAV, JPEG, PNG, GIF, and BMP. |
| 5 | MessagingSMS and MMS |
| 6 | Web browserBased on the open-source WebKit layout engine, coupled with Chrome’s V8 JavaScript engine supporting HTML5 and CSS3. |
| 7 | Multi-touchAndroid has native support for multi-touch which was initially made available in handsets such as the HTC Hero. |
| 8 | Multi-taskingUser can jump from one task to another and same time various application can run simultaneously. |
| 9 | Resizable widgetsWidgets are resizable, so users can expand them to show more content or shrink them to save space. |
| 10 | Multi-LanguageSupports single direction and bi-directional text. |
| 11 | GCMGoogle Cloud Messaging (GCM) is a service that lets developers send short message data to their users on Android devices, without needing a proprietary sync solution. |
| 12 | Wi-Fi DirectA technology that lets apps discover and pair directly, over a high-bandwidth peer-to-peer connection. |
| 13 | Android BeamA popular NFC-based technology that lets users instantly share, just by touching two NFC-enabled phones together. |
Android Applications
- Android applications are usually developed in the Java language using the Android Software Development Kit.
- Once developed, Android applications can be packaged easily and sold out either through a store such as Google Play, SlideME, Opera Mobile Store, Mobango, F-droid and the Amazon Appstore.
- Android powers hundreds of millions of mobile devices in more than 190 countries around the world. It’s the largest installed base of any mobile platform and growing fast. Every day more than 1 million new Android devices are activated worldwide.
Categories of Android applications
There are many android applications in the market. The top categories are −
History of Android
The code names of android ranges from A to N currently, such as Aestro, Blender, Cupcake, Donut, Eclair, Froyo, Gingerbread, Honeycomb, Ice Cream Sandwich, Jelly Bean, KitKat, Lollipop and Marshmallow. Let’s understand the android history in a sequence.
Android Architecture
android architecture or Android software stack is categorised into five parts:
- linux kernel
- native libraries (middleware),
- Android Runtime
- Application Framework
- Applications
Let’s see the android architecture first.
1) Linux kernel
It is the heart of android architecture that exists at the root of android architecture. Linux kernel is responsible for device drivers, power management, memory management, device management and resource access.
2) Native Libraries
On the top of linux kernel, there are Native libraries such as WebKit, OpenGL, FreeType, SQLite, Media, C runtime library (libc) etc. The WebKit library is responsible for browser support, SQLite is for database, FreeType for font support, Media for playing and recording audio and video formats.
3) Android Runtime
In android runtime, there are core libraries and DVM (Dalvik Virtual Machine) which is responsible for running android applications. DVM is like JVM but it is optimised for mobile devices. It consumes less memory and provides fast performance.
4) Android Framework
On the top of Native libraries and android runtime, there is an android framework. Android framework includes Android APIs such as UI (User Interface), telephony, resources, locations, Content Providers (data) and package managers. It provides a lot of classes and interfaces for android application development.
5) Applications
On the top of the android framework, there are applications. All applications such as home, contact, settings, games, browsers are using android framework that uses android runtime and libraries. Android runtime and native libraries are using the linux kernel.
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