The Android OS is a platform for mobile devices which is developed by Android Inc. which was later taken over by Google. The operating system is programmed in the C language. The structure of the Android OS is quite traditional but very efficient.
An application is a component of the Android operating system. The core applications in the operating system are SMS program, calendar, browser, maps, contacts and an email client. Java programming language is used to write all these applications. The application framework is another component of the platform. It is an open development platform that enables developers to use the same framework APIs to write their applications that are used by the core applications. The next major component of the OS is the Libraries. The libraries contain some C/C++ libraries that are used by all components of the OS. System C library is a core library present in this component and used by application programmers to design their programs.
There is also a media library which supports the playback of many audio and video formats. It also displays pictures and photos in many formats. The other core libraries in this component include the surface manager, SGL which is the 2D graphics engine, 3D libraries and SQlite which is a relational database library. There is another core component known as the Android runtime included in the OS. This component has a program called as the Dalvik virtual machine (Dalvik VM). Dalvik is written in such a way that multiple VMs can be run by a device quite efficiently. The execution of files in Dalvik VM is carried out in the .dex format.
The Linux kernel performs the low-level management of memory and threading in the Dalvik VM. The Linux Kernel is the last component of the OS but is very important for its working. Security, process management, network stack, memory management and driver model are the basic system services that are provided by the linux kernel. A level of abstraction between the hardware and the software stack is maintained by the linux kernel.
In this way, the Android OS is designed to work effectively and this design makes it one of the popular operating systems for mobile phones.
