Android Programming - Day One

1. 1. What is Android?

Android is a mobile operating system that is based on a modified version of Linux. It was first developed by a startup company with name Android Inc. In 2005, Google purchased it and took over its development work.

2. 2. Android Versions

The following table shows a brief history of Android Versions which are based on different types of fruit names along with release date.

3. Architecture

It is very important to know about the architecture of the Android operating system before start programming for Android application development.

The Android Operating System is roughly into five sections in four main layers.

• 3.1 Linux Kernel - Android is based on Linux Kernel. This layer contains all the low-level device drivers for the various hardware components.
• 3.2 Libraries – It contains all the code that provides the main features of an Android OS. e.g Libraries of SQLite, WebKit, etc.
• 3.3 Android Runtime- It provides a set of core libraries that enable developers to write Android apps using the Java Programming Language. It also includes the Dalvik virtual machine, which enables every Android application to run in its own process.
• 3.4 Application Framework- It exposes the various capabilities of the OS to application developers to use them in the applications.
• 3.5 Applications-Any applications that the developers write are located in this layer.