Android is
an operating
system based on the Linux kernel with
a user
interface based on direct manipulation,
designed primarily for touchscreen mobile
devices such as smartphones and tablet computers,
using touch inputs, that loosely correspond to real-world actions, like
swiping, tapping, pinching, and reverse pinching to manipulate on-screen
objects, and a virtual keyboard.
Despite being primarily designed for touchscreen input, it also has been used
in televisions, games
consoles, digital cameras,
and other electronics. Initially developed by Android, Inc., which Google backed
financially and later bought in 2005, Android was unveiled in 2007 along
with the founding of the Open
Handset Alliance—a consortium of hardware,
software, and telecommunication companies devoted to advancing open standards for
mobile devices. The first publicly available smartphone running Android,
the HTC Dream,
was released on October 22, 2008 As. of 2011, Android has the largest
installed base of any mobile
OS and as of 2013, its devices also sell more than
Windows, iOS and Mac OS devices combined.
As of July 2013 the Google Play store
has had over 1 million Android apps published, and over 50 billion apps
downloaded. A developer survey conducted in April–May 2013 found that 71%
of mobile developers develop for Android.
Android's source code is
released by Google under open source licenses,
although most Android devices ultimately ship with a combination of open source
and proprietary software. Android is popular with technology companies
which require a ready-made, low-cost and customizable operating system
for high-tech devices Android's
open nature has encouraged a large community of developers and enthusiasts to
use the open-source code as a foundation for community-driven projects, which
add new features for advanced users or bring Android to devices which were
officially released running other operating systems. The operating system's
success has made it a target for patent litigation as part of the so-called
"smartphone
wars" between technology companies.
History
Android, Inc. was founded in Palo
Alto, California in October 2003 by Andy Rubin (co-founder
of Danger), Rich Miner (co-founder
of Wildfire Communications, Inc.), Nick Sears (once VP at T-Mobile),
and Chris White (headed design and interface development at WebTV) to
develop, in Rubin's words "smarter mobile devices that are more aware of
its owner's location and preferences". The early intentions of the
company were to develop an advanced operating system for digital
cameras, when it was realised that the market for the devices
was not large enough, and diverted their efforts to producing a smartphone
operating system to rival those of Symbian and Windows Mobile. Despite
the past accomplishments of the founders and early employees, Android Inc.
operated secretly, revealing only that it was working on software for mobile
phones. That same year, Rubin ran out of money.Steve Perlman,
a close friend of Rubin, brought him $10,000 in cash in an envelope and refused
a stake in the company.
Google acquired
Android Inc. on August 17, 2005; key employees of Android Inc., including
Rubin, Miner, and White, stayed at the company after the acquisition. Not
much was known about Android Inc. at the time, but many assumed that Google was
planning to enter the mobile phone market with this move. At Google, the
team led by Rubin developed a mobile device platform powered by the Linux kernel.
Google marketed the platform to handset makers and carriers on
the promise of providing a flexible, upgradable system. Google had lined up a
series of hardware component and software partners and signaled to carriers
that it was open to various degrees of cooperation on their part.
Speculation about
Google's intention to enter the mobile communications market continued to build
through December 2006. The unveiling of the iPhone,
a touchscreen-based
phone by Apple,
on January 9, 2007 had a disruptive effect
on the development of Android. At the time, a prototype device codenamed
"Sooner" had a closer resemblance to a BlackBerry phone,
with no touchscreen, and a physical, QWERTY keyboard.
Work immediately began on re-engineering the OS and its prototypes to combine
traits of their own designs with an overall experience designed to compete with
the iPhone. In September 2007, InformationWeek covered
an Evalueserve study
reporting that Google had filed several patent applications in the area of
mobile telephony.
In 2010, Google
launched its Nexus series
of devices – a line of smartphones and tablets running the Android
operating system, and built by a manufacturing partner. HTC collaborated with
Google to release the first Nexus smartphone, the Nexus One.
The series has since been updated with newer devices, such as the Nexus 5 phone
and Nexus 7 tablet, made
by LG and Asus respectively.
Google releases the Nexus phones and tablets to act as their flagship Android
devices, demonstrating Android's latest software and hardware features. On
March 13, 2013, it was announced by Larry Page in
a blog post that Andy Rubin had moved from the Android division to take on new
projects at Google. He was replaced by Sundar Pichai,
who also continues his role as the head of Google's Chrome division, which
develops Chrome
OS.On November 5, 2007, the Open
Handset Alliance, a consortium of
technology companies including Google, device manufacturers such as HTC, Sony and Samsung,
wireless carriers such as Sprint Nextel and T-Mobile,
and chipset makers such as Qualcomm and
Texas
Instruments, unveiled itself, with a goal to
develop open
standards for mobile devices. That day,
Android was unveiled as its first product, a mobile device platform built
on the Linux
kernel version 2.6.25. The first commercially
available smartphone running Android was the HTC Dream,
released on October 22, 2008.
Since 2008, Android
has seen numerous
updates which have incrementally improved the operating
system, adding new features and fixing bugs in previous releases. Each major
release is named in alphabetical order after a dessert or sugary treat; for
example, version 1.5 Cupcake was followed by 1.6 Donut.
The latest released version is 4.4.2 KitKat,
which was released on December 9, 2013.
Interface
Notifications are
accessed by sliding from the top of the display; individual notifications can
be dismissed by sliding them away, and may contain additional functions (such
as on the "missed call" notification seen here).
Android's default user
interface is based on direct
manipulation, using touch inputs, that loosely
correspond to real-world actions, like swiping, tapping, pinching, and reverse
pinching to manipulate on-screen objects, and a virtual keyboard. The
response to user input is designed to be immediate and provides a fluid touch
interface, often using the vibration capabilities of the device to
provide haptic
feedback to the user. Internal hardware
such as accelerometers, gyroscopes and proximity sensors are
used by some applications to respond to additional user actions, for example
adjusting the screen from portrait to landscape depending on how the device is
oriented, or allowing the user to steer a vehicle in a racing game by rotating
the device, simulating control of a steering wheel.
Android devices boot to the homescreen,
the primary navigation and information point on the device, which is similar to
the desktop found
on PCs. Android homescreens are typically made up of app icons and widgets;
app icons launch the associated app, whereas widgets display live,
auto-updating content such as the weather forecast, the user's email inbox, or
a news
ticker directly on the homescreen. A homescreen
may be made up of several pages that the user can swipe back and forth between,
though Android's homescreen interface is heavily customisable, allowing the
user to adjust the look and feel of the device to their tastes. Third-party
apps available on Google
Play and other app stores can extensively re-theme the
homescreen, and even mimic the look of other operating systems, such as Windows Phone. Most
manufacturers, and some wireless
carriers, customise the look
and feel of their Android devices to differentiate themselves from their
competitors.
Present along the top of the screen is a
status bar, showing information about the device and its connectivity. This
status bar can be "pulled" down to reveal a notification screen where
apps display important information or updates, such as a newly received email
or SMS text, in a way that does not immediately interrupt or inconvenience the
user. Notifications are persistent until read (by tapping, which opens the
relevant app) or dismissed by sliding it off the screen. Beginning on Android
4.1, "expanded notifications" can display expanded details or
additional functionality; for instance, a music player can display playback
controls, and a "missed call" notification provides buttons for
calling back or sending the caller an SMS message.
Android provides the ability to run
applications which change the default launcher and hence the appearance and
externally visible behaviour of Android. These appearance changes include a
multi-page dock or no dock, and many more changes to fundamental features of
the user interface.
Applications
Android has a growing selection of third
party applications, which can be acquired by users either through an app store
such as Google
Play or the Amazon Appstore,
or by downloading and installing the application's APK file
from a third-party site. Google Play Store allows users to browse,
download and update applications published by Google and third-party
developers, and the Play Store client application is pre-installed on devices
that comply with Google's compatibility requirements and license the Google
Mobile Services software. The client application filters the list of
available applications down to those compatible with the user's device, and
developers may restrict their applications to particular carriers or countries
for business reasons. Purchases of unwanted applications can be refunded
within 15 minutes of the time of download, and some carriers offer direct
carrier billing for Google Play application purchases, where the cost of the
application is added to the user's monthly bill.
As of July 2013, there are more than one
million applications available for Android in Play Store As of May 2013,
48 billion apps have been installed from Google Play store.
Applications ("apps"),
that extend the functionality of devices, are developed primarily in the Java programming
language language using the Android
software development kit (SDK). The SDK includes a
comprehensive set of development tools, including a debugger, software libraries,
a handset emulator based
on QEMU,
documentation, sample code, and tutorials. The officially supported integrated development environment (IDE)
is Eclipse using
the Android Development Tools (ADT) plugin. Other development tools are
available, including a Native
Development Kit for applications or
extensions in C or C++, Google
App Inventor, a visual environment for novice
programmers, and various cross platform mobile web
applications frameworks.
It was announced in January 2014
that Chrome HTML5
web applications should become available, using a compatibility layer from the
open source Apache
Cordova framework to allow such applications to be
wrapped in a native application shell, enabling their distribution over Google
Play.
Memory management
Since Android devices are usually
battery-powered, Android is designed to manage memory (RAM)
to keep power consumption at a minimum, in contrast to desktop operating
systems which generally assume they are connected to unlimited mains electricity. When
an Android app is no longer in use, the system will automatically suspend it in
memory – while the app is still technically "open", suspended apps
consume no resources (for example, battery power or processing power) and sit
idly in the background until needed again. This has the dual benefit of
increasing the general responsiveness of Android devices, since applications do
not need to be closed and reopened from scratch each time, and also ensuring
that background applications do not consume power needlessly.
Android manages the apps stored in
memory automatically: when memory is low, the system will begin killing apps
and processes that have been inactive for a while, in reverse order since they
were last used (oldest first). This process is designed to be invisible to the
user, such that users do not need to manage memory or the killing of apps
themselves. However, confusion over Android memory management has resulted
in third-party task killers becoming popular on Google Play store;
these third-party task killers are generally regarded as doing more harm than
good.
0 Response to "Gadget- Android"
Posting Komentar