Step 1 - System Requirements : You will be delighted, to know that you can start your Android application development on either of the following operating systems −
- Microsoft® Windows® 8/7/Vista/2003 (32 or 64-bit).
- Mac® OS X® 10.8.5 or higher, up to 10.9 (Mavericks)
- GNOME or KDE desktop
- Java JDK5 or later version
- Java Runtime Environment (JRE) 6
- Android Studio
Step 2 - Setup Android Studio
Overview
Android Studio is the official IDE for android application development.It works based onIntelliJ IDEA, You can download the latest version of android studio from Android Studio Download, If you are new to installing Android Studio on windows,you will find a file, which is named as android-studio-bundle-135.17407740-windows.exe.So just download and run on windows machine according to android studio wizard guideline.If you are installing Android Studio on Mac or Linux, You can download the latest version from Android Studio Mac Download,or Android Studio Linux Download, check the instructions provided along with the downloaded file for Mac OS and Linux. This tutorial will consider that you are going to setup your environment on Windows machine having Windows 8.1 operating system.
Installation
So let's launch Android Studio.exe,Make sure before launch Android Studio, Our Machine should required installed Java JDK. To install Java JDK,take a references of Android environment setup
Once you launched Android Studio, its time to mention JDK5 path or later version in android studio installer.
Below the image initiating JDK to android SDK
Need to check the components, which are required to create applications, below the image has selected Android Studio,Android SDK,Android Virtual Machine and performance(Intel chip).
Need to specify the location of local machine path for Android studio
and Android SDK, below the image has taken default location of windows
8.1 x64 bit architecture.
Need to specify the ram space for Android emulator by default it would take 512MB of local machine RAM
At final stage, it would extract SDK packages into our local machine,
it would take a while time to finish the task and would take 2626MB of
Hard disk space. 
After done all above steps perfectly, you must get finish button and
it gonna be open android studio project with Welcome to android studio
message as shown below
You can start your application development by calling start a new
android studio project. in a new installation frame should ask
Application name, package information and location of the project.
After entered application name, it going to be called select the form
factors your application runs on, here need to specify Minimum SDK, in
our tutorial, I have declared as API21: Android 5.0(Lollipop)
The next level of installation should contain selecting the activity to mobile, it specifies the default layout for Applications
At the final stage it going to be open development tool to write the application code.
Step 3 - Create Android Virtual Device
To test your Android applications, you will need a virtual Android device. So before we start writing our code, let us create an Android virtual device. Launch Android AVD Manager Clicking AVD_Manager icon as shown below
After Click on a virtual device icon, it going to be shown by default
virtual devices which are present on your SDK, or else need to create a
virtual device by clicking Create new Virtual device button
If your AVD is created successfully it means your environment is
ready for Android application development. If you like, you can close
this window using top-right cross button. Better you re-start your
machine and once you are done with this last step, you are ready to
proceed for your first Android example but before that we will see few
more important concepts related to Android Application Development.Hello Word Example
Before Writing a Hello word code, you must know about XML tags.To write hello word code, you should redirect to App>res>layout>Activity_main.xml
To show hello word, we need to call text view with layout ( about text view and layout, you must take references at Relative Layout and Text View ). xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">
android:text="@string/hello_world"
android:layout_width="550dp"
android:layout_height="wrap_content" />
