What is android?
Android is a mobile operating system (OS) currently developed by Google, based on the Linux kernel and designed primarily for touchscreen mobile devices such as smartphones and tablets. It has been the best-selling OS on tablets and on smartphones since 2013, and has the largest installed base.
Android's user interface is mainly based on direct manipulation, using touch gestures that loosely correspond to real-world actions, such as swiping, tapping and pinching, to manipulate on-screen objects, along with a virtual keyboard for text input. The operating system's current design language is Google's Material Design. Android's primary app store is Google Play, with over one million Android applications ("apps") published and 50 billion downloads as of July 2013. In addition to touchscreen devices, Google has further developed Android for television, cars, and wristwatches, each with a specialized yet similar interface. Variants and forked versions of Android are also used on notebooks, game consoles, digital cameras, and other electronics.
Features in Android
General
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Messaging
- SMS and MMS are available forms of messaging, including threaded text messaging and Android Cloud To Device Messaging (C2DM) and now enhanced version of C2DM, Android Google Cloud Messaging (GCM) is also a part of Android Push Messaging services.
Web browser
- The web browser available in Android is based on the open-source Blink (previously WebKit) layout engine, coupled with Chrome's V8 JavaScript engine. Then the WebKit-using Android Browser scored 100/100 on the Acid3 test on Android 4.0 ICS; the Blink-based browser currently has better standards support. The browser is variably known as 'Android Browser', 'AOSP browser', 'stock browser', 'native browser', and 'default browser'. Starting with Android 4.4 KitKat, Google has mandated that the default browser for Android proper be Google Chrome. Since Android 5.0 Lollipop, the WebView browser that apps can use to display web content without leaving the app has been separated from the rest of the Android firmware in order to facilitate separate security updates by Google.
Voice-based features
- Google search through voice has been available since initial release. Voice actions for calling, texting, navigation, etc. are supported on Android 2.2 onwards. As of Android 4.1, Google has expanded Voice Actions with ability to talk back and read answers from Google's Knowledge Graph when queried with specific commands. The ability to control hardware has not yet been implemented.
- Multi-touch
- Android has native support for multi-touch which was initially made available in handsets such as the HTC Hero. The feature was originally disabled at the kernel level (possibly to avoid infringing Apple's patents on touch-screen technology at the time). Google has since released an update for the Nexus One and the Motorola Droid which enables multi-touch natively.
- Multitasking
- Multitasking of applications, with unique handling of memory allocation, is available.
- Screen capture
- Android supports capturing a screenshot by pressing the power and home-screen buttons at the same time. Prior to Android 4.0, the only methods of capturing a screenshot were through manufacturer and third-party customizations (apps), or otherwise by using a PC connection (DDMS developer's tool). These alternative methods are still available with the latest Android.
- TV recording
- Android TV supports capturing video and replay it.
- Video calling
- Android does not support native video calling, but some handsets have a customized version of the operating system that supports it, either via the UMTS network (like the Samsung Galaxy S) or over IP. Video calling through Google Talk is available in Android 2.3.4 (Gingerbread) and later. Gingerbread allows Nexus S to place Internet calls with a SIP account. This allows for enhanced VoIP dialing to other SIP accounts and even phone numbers. Skype 2.1 offers video calling in Android 2.3, including front camera support. Users with the Google+ Android app can video chat with other Google+ users through Hangouts.
- Multiple language support
- Android supports multiple languages.
- Accessibility
- Built-in text-to-speech is provided by TalkBack for people with low or no vision. Enhancements for people with hearing difficulties are available, as are other aids.
Connectivity
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- Connectivity
- Android supports connectivity technologies including GSM/EDGE, Bluetooth, LTE, CDMA, EV-DO, UMTS, NFC, IDEN and WiMAX.
- Bluetooth
- Supports voice dialing and sending contacts between phones, playing music, sending files (OPP), accessing the phone book (PBAP), A2DP and AVRCP. Keyboard, mouse and joystick (HID) support is available in Android 3.1+, and in earlier versions through manufacturer customization's and third-party applications.
- Tethering
- Android supports tethering, which allows a phone to be used as a wireless/wired Wi-Fi hotspot. Before Android 2.2 this was supported by third-party applications or manufacturer customization's.
Media
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- Streaming media support
- RTP/RTSP streaming (3GPP PSS, ISMA), HTML progressive download (HTML5 <video> tag). Adobe Flash Streaming (RTMP) and HTTP Dynamic Streaming are supported by the Flash plugin. Apple HTTP Live Streaming is supported by RealPlayer for Android, and by the operating system since Android 3.0 (Honeycomb).
- Media support
- Android supports the following audio/video/still media formats: WebM, H.263, H.264, AAC, HE-AAC (in 3GP or MP4 container), MPEG-4 SP, AMR, AMR-WB (in 3GP container), MP3, MIDI, Ogg Vorbis, FLAC, WAV, JPEG, PNG, GIF, BMP, and WebP.
- External storage
- Most Android devices include microSD card slots and can read microSD cards formatted with the FAT32, Ext3 or Ext4 file systems. To allow use of external storage media such as USB flash drives and USB HDDs, some Android devices are packaged with USB-OTG cables. Storage formatted with FAT32 is handled by the Linux Kernel vFAT driver, while 3rd party solutions are required to handle some other file systems such as NTFS, HFS Plus and exFAT.
Hardware support
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Android devices can include still/video cameras, touchscreens, GPS, accelerometers, gyroscopes, barometers, magnetometers, dedicated gaming controls, proximity and pressure sensors, thermometers, accelerated 2D bit blits (with hardware orientation, scaling, pixel format conversion) and accelerated 3D graphics.Other
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- Java support
- While most Android applications are written in Java, there is no Java Virtual Machine in the platform and Java byte code is not executed. Java classes are compiled into Dalvik executables and run on using Android Runtime or in Dalvik in older versions, a specialized virtual machine designed specifically for Android and optimized for battery-powered mobile devices with limited memory and CPU. J2ME support can be provided via third-party applications.
- Handset layouts
- The platform works for various screen sizes from smartphone sizes and to tablet size, and can potentially connect to an external screen, e.g. through HDMI, or wirelessly with Miracast. Portrait and landscape orientations are supported and usually switching between by turning. A 2D graphics library, 3D graphics library based on OpenGL ES 2.0 specifications is used.
- Storage
- SQLite, a lightweight relational database, is used for data storage purposes.
- Native Apps
- Android apps are also written in HTML.
