Android Overview
What is Android?
Android provides a unified approach to application development, meaning developers only need to develop for Android, allowing their applications to run on different mobile devices powered by Android.
Google released the first test version of the Android Software Development Kit (SDK) in 2007, and 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 release of Android version 4.1 Jelly Bean. Jelly Bean is an incremental update in terms of features and performance, primarily aimed at improving the user interface.
The Android source code is licensed under free and open-source software licenses. Most of the code released by Google follows the Apache License, Version 2.0, and changes to the Linux kernel follow the GNU General Public License, Version 2.
Advantages of Android Development
- Open source
- Numerous developers and a strong community
- Growing market
- International app integration
- Low development costs
- Higher success probability
- Rich development environment
Features of Android
Android is a powerful operating system competing with Apple's 4GS and supports great features. Some of the features are listed below:
| Feature | Description |
|---|---|
| Beautiful UI | The basic screen of the Android operating system provides a beautiful and intuitive user interface. |
| Connectivity | GSM/EDGE, IDEN, CDMA, EV-DO, UMTS, Bluetooth, Wi-Fi, LTE, NFC, and WiMAX. |
| Storage | Lightweight relational database SQLite for data storage |
| Media Support | H.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 |
| Messaging | SMS and MMS |
| Web Browser | Based on the open-source WebKit layout engine, plus support for HTML5 and CSS3 with Chrome's V8 JavaScript engine. |
| Multi-touch | Android natively supports multi-touch, which has been present since the initial handheld devices like the HTC Hero. |
| Multi-tasking | Users can switch from one task to another and can run applications simultaneously. |
| Adjustable Widgets | Widgets are resizable, so users can expand them for more content or shrink them to save space. |
| Multi-language | Supports both left-to-right and right-to-left text directions. |
| GCM | Google Cloud Messaging (GCM) is a service that allows developers to send short message data to users of Android devices without a proprietary sync solution. |
| Wi-Fi Direct | A technology for direct discovery and pairing of applications through high-bandwidth peer-to-peer connections. |
| Android Beam | A popular NFC-based technology that allows users to instantly share information by simply touching two NFC-enabled phones together. |
Android Applications
Android applications are typically developed using the Android Software Development Kit and the Java programming language.
Once developed, Android applications can be easily packaged and sold on platforms such as Google Play and the Amazon Appstore.
Android is available in over 190 countries worldwide and has millions of mobile devices. It is the largest and fastest-growing installation base of any mobile platform. More than 1 million new Android devices are activated every day globally.
This tutorial aims to teach you how to develop and package Android applications. We will start with setting up the Android application programming environment and then delve into various aspects of Android application development.
Categories of Android Applications
There are many Android applications on the market. The main categories include:
History of Android
Android's code names have ranged from A to L, including Aestro, Blender, Cupcake, Donut, Eclair, Froyo, Gingerbread, Honeycomb, Ice Cream Sandwich, Jelly Bean, KitKat, and Lollipop. Let's explore the history of Android in order.
- Cupcake
- Donut
- Eclair
- Froyo
- Gingerbread
- Honeycomb
- Ice Cream Sandwich
- Jelly Bean
- KitKat
- Lollipop
What is API Level?
The API level is an integer that uniquely identifies the version of the API framework provided by a version of the Android platform.
| Platform Version | API Level | VERSION_CODE | |
|---|---|---|---|
| Android 5.1 | 22 | LOLLIPOP_MR1 | |
| Android 5.0 | 21 | LOLLIPOP | |
| Android 4.4W | 20 | KITKAT_WATCH | KitKat for Wearables Only |
| Android 4.4 | 19 | KITKAT | |
| Android 4.3 | 18 | JELLY_BEAN_MR2 | |
| Android 4.2, 4.2.2 | 17 | JELLY_BEAN_MR1 | |
| Android 4.1, 4.1.1 | 16 | JELLY_BEAN | |
| Android 4.0.3, 4.0.4 | 15 | ICE_CREAM_SANDWICH_MR1 | |
| Android 4.0, 4.0.1, 4.0.2 | 14 | ICE_CREAM_SANDWICH | |
| Android 3.2 | 13 | HONEYCOMB_MR2 | |
| Android 3.1.x | 12 | HONEYCOMB_MR1 | |
| Android 3.0.x | 11 | HONEYCOMB | |
| Android 2.3.4, Android 2.3.3 | 10 | GINGERBREAD_MR1 | |
| Android 2.3.2, Android 2.3.1, Android 2.3 | 9 | GINGERBREAD | |
| Android 2.2.x | 8 | FROYO | |
| Android 2.1.x | 7 | ECLAIR_MR1 | |
| Android 2.0.1 | 6 | ECLAIR_0_1 | |
| Android 2.0 | 5 | ECLAIR | |
| Android 1.6 | 4 | DONUT | |
| Android 1.5 | 3 | CUPCAKE | |
| Android 1.1 | 2 | BASE_1_1 | |
| Android 1.0 | 1 | BASE |