Android System Architecture

The underlying Android system is built on a Linux system, such as

You can see that there are five parts of the Android system

1.APPLICATIONS (Application layer)

Contains some core applications, emails, calendars, maps, browsers, etc.

2.APPLICATION Framework (Application framework)

Android application Framework provides a large number of APIs for developers to use, it is recommended to download the Android API from the Internet or online browsing is ok (http://www.android-doc.com/reference/packages.html)

Any application can publish some of its functional modules, which are available to other developers as long as they are posted with the framework's conventions.

3.LIBRARIES (function library)

Android consists of a set of C + + libraries used by different components. In general, Android app developers cannot call this set of C/+ + libraries directly, but they can be called through the application framework above it.

Some of the core libraries are listed below.

---System C library: A standard C system library (LIBC) derived from the BSD system and tuned specifically for embedded Linux devices.

---Media Library: PacketVideo-based Opencore, which supports the playback and recording of many popular audio and video formats, as well as viewing static images. Mainly include MPEG4, H. MP3, AAC, AMR, JPG, PNG and other multimedia formats.

--Surface Manager: Manages access to the display subsystem and provides seamless integration of 2D and 3D layer machines from multiple applications.

--Libwebcore: A brand new Web browser engine that supports Android browsers and supports WebView, WebView can be embedded in the developer's own application.

--SGL: The underlying 2D graphics engine.

-- -3d libraries: 3D system based on the OpenGL ES 1.0 API, this 3D system can use either hardware 3D acceleration or highly optimized software 3D acceleration.

---FreeType: bitmap and vector font display.

---sqlite: A lightweight, powerful relational database for use by all applications.

4.ANDROID RUNTIME

Android runtime consists of two parts: the Android Core Class library set and the Dalvik virtual machine. The Core class library set provides most of the functionality that the Java language Core library can use, and the virtual machine is responsible for running Android applications.

5.Linux kernel

The Android system is built on Linux 2.6. The Linux kernel provides core system services such as security, memory management, process management, network protocol stacks, and drive models.

Android System Architecture