Android is a Linux-based mobile operating system developed by the Google-led Open Handset Alliance. Android is mainly used on smartphones and tablets. Android is open source, meaning its functionality can be extended to incorporate new technologies as they emerge.

Android, Inc. was founded by Andy Rubin, Rich Miner, Nick Sear, and Chris White in Palo Alto, California. On August 17, 2005, Google acquired Android Inc. making it a subsidiary of Google Inc.

On November 5, 2007, the Open Handset Alliance publicly announced its first product, Android, a platform for mobile devices based on version 2.6 of the Linux kernel.

Android provides a wide spectrum of applications and services to its users. Users can fully customize their mobile phones according to their interests. The first mobile phone to use Android was the HTC Dream, released on October 22, 2008.

These are some features of the Android operating system.

1. Design: Design is mainly based on VGA, 2D graphics library and 3D graphics library based on OpenGL ES 2.0.
2. Storage: SQLite is used for data storage.
3. connectivity: Android supports GSM/EDGE, IDEN, CDMA, EV-DO, UMTS, Bluetooth, WI-Fi, LTE, NFC, and WiMAX connectivity technologies.
4. multilingual support: It supports multiple languages.
5. Messenger service: Android supports SMS and MMS, including threaded text messages and Cloud-to-Device Messaging (C2DM).
6. Web navigator: Primarily based on the open source WebKit layout engine and Chrome’s V8 JavaScript engine.
7. java support: Most applications are written in Java but run on Dalvik, a specialized virtual machine designed specifically for Android.
8. media support: Android supports WebM, H.263, H.264, MPEG-4 SP, AMR, AMR-WB, AAC, HE-AAC, MP3, MIDI, Ogg Vorbis, FLAC, WAV, JPEG, PNG, GIF, BMP, and WebP media formats.
9. hardware support– Can support a wide variety of hardware, including video/still cameras, touch screens, GPS, accelerometers, gyroscopes, barometers, magnetometers, dedicated game controllers, proximity and pressure sensors, thermometers, accelerated 2D bit blits, and 3D graphics accelerated.
10. multitask: Android supports multitasking.
11. multi-touch: Supports multitouch natively, but was previously disabled at the kernel level. Google released an update that enables multi-touch natively.
12. external supportNote: Most Android devices now support microSD slot and can read microSD cards formatted with FAT32, Ext3fs or Ext4fs file system.

There are millions of apps available for Android that can be downloaded from Google Play, formerly Android Market. The latest version that is available for phones is Android 4.0.4 Ice Cream Sandwich.