Google Adroid Architecture

The following diagram shows the major components of the Android operating system. Each section is described in more detail below.

Getting Started with Android

To get started with Android, please read the following sections first:

Installing the SDK and Plugin

How to install the Android SDK and Eclipse plugin.

Developing and Debugging

An introduction to developing and debugging Android applications in Eclipse, plus information on using other IDEs.

Hello Android

Writing your first Android Application, the ever popular Hello World, Android style.

Anatomy of an App

A guide to the structure and architecture of an Android Application. This guide will help you understand the pieces that make up an Android app.

Notepad Tutorial

This tutorial document will lead you through constructing a real Android Application: A notepad which can create, edit and delete notes, and covers many of the basic concepts with practical examples.

Development Tools

The command line tools included with the SDK, what they do, and how to use them.

Application Model

A guide to Applications, Tasks, Processes, and Threads. These are the elements that define the way your application is run by the system and presented to the user.

Application Life Cycle

The important life-cycle details for Applications and the Activities running inside of them.

Other Introductory Material

After reading the sections above, the following Getting Started information is also very useful:

Core Packages

These are the basic packages that make up the Android SDK for writing applications. The packages are organized as layers, listed here from lowest-level to highest.

android.util

contains various low-level utility classes, such as specialized container classes, XML utilities, etc.

android.os

provides basic operating system services, message passing, and inter-process communication.

android.graphics

is the core rendering package.

android.text, android.text.method, android.text.style, and android.text.util

supply a rich set of text processing tools, supporting rich text, input methods, etc.

android.database

contains low-level APIs for working with databases.

android.content

provides various services for accessing data on the device: applications installed on the device and their associated resources, and content providers for persistent dynamic data.

android.view

is the core user-interface framework.

android.widget

supplies standard user interface elements (lists, buttons, layout managers, etc) built from the view package.

android.app

provides the high-level application model, implemented using Activities.

Other Notable Packages

These packages provide additional domain-specific features of the Android platform. They are not necessary for basic application development.

android.provider

contains definitions for various standard content providers included with the platform.

android.telephony

provides APIs for interacting with the device's phone stack.

android.webkit

includes various APIs for working with web-based content.