Key Concepts

Welcome Again!!

So, I suppose that you have an idea of what Android is, let's take a look at how it works. Some parts of Android may be similar, such as the Linux Kernel, OpenGL,SQL Database and others will be completely foreing, but don`t worry, it's simple.


Let`s start by taking a look at he overall system architecture.

As you can see, this is the architecture of Android, the key layers and components that make up android.
Each layer uses the services provided by the layers below it.

The key layers :

• Linux Kernel - Android is built on top of a solid and proven foundation, Linux. Android uses Linux for its memory and process management, networking and many operations system services.

• Libraries  - The next layer above kernel contains the Android native Libraries, some of the most important libraries include:
• Surface Manager  - use's a compositing window manager cimilar to Vista or Compiz. Instead of drawing directly to the screen buffer, your drawing commands go into off-screen bitmaps that are then combined with other bitmaps to form the display the user sees.
• 2D and 3D - The library will use 3D hardware if the device has it or a fast software renderer if it doesn`t.
• Media Codecs  - Android can play video and record and play back audio in a variety of formats.
• SQL Database - Android use a lightweight SqLite Databse engine, the same of Firefox.
• Browser Engine - For the  fast display of HTML content, Android uses the WebKit library, this is the same library  used in the Chrome.

• Android Runtime - Also sitting on top of the kernel is the Android Runtime, this library is very important to understand, include the Dalvik virtual machine. Basically all code you write for Android will be written in Java and run within the virtual machine of Dalvik, he convert at compile time from standard .class and .jar files .dex files are more compact and efficient than class files, an important consideration for the limited memory and battery powered devices that Android target.

• Application Framework -  This layer provides the high-level building blocks you will see use to create your applications, the Framework comes pre-installed with Android, but also you can extend it with your own component as needed.

It`s important that you really understand the Android application life cycle.
Tomorrow I will explain you the application life cycle, each is very important when developing for Android.    

Welcome

Android as Goal, is a small blog where you will learn to create apps for Android S.O.
Google`s Android operating-system has taken the industry by storm, going from its humble beginnings as a smartphone operating system to its current status as a platform for apps that run across a gamut of devices from phones to tablets to netbooks to televisions, and the list is sure to grow.