Android Architecture?
Ans:-
Android operating system is a stack of software components which is roughly divided into five sections and four main layers.
Linux kernel:
At the bottom of the layers is Linux.That provides basic system functionality like memory management, process management, device management like keypad, display,camera etc. Karnel also handels device drivers.
Libraries:
On top of Linux kernel on the second layer there is a set of libraries.These contain all the code that provides the main features of an Android OS. For example, the SQLite library provides database support so that an application can use it for data storage. The WebKit library provides functionalities for web browsing.
Android Runtime:
This is the third section of the architecture and available on the second layer from the bottom. The Android runtime provides a set of core libraries that enable developers to write Android apps using the Java programming language. The Android runtime also includes the Dalvik virtual machine(DVM), this helps in running android apps(android applications are compiled into Dalvik executables).
Application Framework:
This is the forth section of the architecture and available on the third layer from the bottom.It exposes the various capabilities of the Android Operating System to application developers so that they can make use of them in their applications.
Applications:
At the top layer there are applications that ship with android device and those you download and install.For example Phone, Contacts, Browser, etc. Any applications that you write are located at this layer.
