An Android™ phone, sometimes called a Droid™ phone, is a mobile telephone that uses the Google-developed Android™ operating system. This operating system has become a popular option in recent years for so-called "smart phones," because developers and manufacturers may freely customize it to their specific needs. This customization means that different Android™ phones can have widely varying user interfaces. Most smart phones — including those using competing operating systems — offer similar overall capabilities, however, including Internet browsing, personal information management, video streaming, and access to a large repository of freeware and payware applications.
Technical Specifications and Operating System
On the technical side, an Android™ phone runs the Android™ operating system, key applications, and middleware. It is Linux® kernel-based, and is written in the C language. Android™ runs applications that are written primarily in the Java® language.
Android™ phones are considered revolutionary in some circles because of the open source structure of the basic firmware. All developers, whether professional or hobbyists, are encouraged to write programs and applications for the operating system, and contribute to the evolving Android™ project by submitting them to Google's Play Store™, a closed source application for Android™ phones. Users may then choose to download and use the applications on their phones by accessing the application library via their handsets.
An Android™ phone can run multiple applications at the same time in the background, making multitasking easier. This makes the functionality of the phone more fluid than some competing platforms, although the extent of this capability depends on the hardware of the individual phone. Some handsets use multicore processors, which are more useful for "power users" who need their phones to run multiple simultaneous operations.
Some comparable devices using other operating systems are governed by strict proprietary rules. Developers interested in writing applications for the iPhone™, for example, may not be permitted to create programs that closely mirror applications owned by Apple, such as iTunes™. All applications must be approved by Apple before they are permitted to appear in the Apple App Store™. This is not the case with applications for Android™ phones, which are developed under the auspices of the Open Handset Alliance, a consortium that encourages the use and advancement of open source software for mobile phones.
Another important distinction of the Android™ platform is that it is not tied to a specific hardware manufacturer. Any manufacturer interested in producing its own version of an Android™ phone is welcome to use the operating system. The result is that many competing cellphone companies now use this platform to power their mobile phones and to market their devices.
Initially, Google partnered with the High Tech Computer Corporation (now HTC Corporation) to build the first mobile phone to run the Android™ platform, known as the G1™ in the United States. In 2008, T-Mobile premiered the G1™ Android™ phone to the American public. Since then, dozens of manufacturers have brought hundreds of phones with this operating system to market.
Different generations of smart phones have run various versions of Android™. Each major software version is identified by a code name that is usually related to some sort of dessert. While many phones can be updated to newer versions of the operating system, this usually cannot be done indefinitely, because of the hardware limitations of the individual phones. For example, early phones like the G1™, which initially ran the 1.0 version of Android™, were eventually upgradable to version 1.6 (Donut), but could not be upgraded to later versions such as 2.3 (Gingerbread) or 4.0 (Ice Cream Sandwich), which require more robust hardware.
Android™ offers a Software Development Kit (SDK) to help developers create functional applications. While some parts of the Android™ operating system are protected under the Apache™ License to guard against applications that could compromise the phones' basic functionality, much of it is released under the General Public License, which invites developers to freely make modifications. The SDK includes extensive resources and tools to facilitate this sort of development. It is updated regularly, together with the operating system itself, and a priority is placed upon supporting work on both newer and older versions of Android™.
Despite the relatively open structure of the operating system, manufacturers of many devices that use Android™ do frequently restrict user access to certain resources and functions within the structure of the software. Typically, manufacturers do this in order to ensure a consistently stable and predictable experience by all users, and possibly to maintain a certain level of control over how their products are used.
"Rooting" is the slang term for using software hacks to circumvent these restrictions in Android™. Some users opt to do this either in order to expand the capabilities of a phone or simply as a hobby and for purposes of experimentation. The process varies, but commonly involves downloading a special file from the Internet and installing it on the phone from an external memory card. Detailed instructions on how to root a specific Android™ phone are broadly available online, though users should be aware that there are risks to doing this. In many cases, rooting will void a phone's warranty, and there is also a potential that a device could be rendered useless should something go wrong.