(Chapter 2) Basic Concepts

·         Architecture

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Application and Widget

Application Frame works

Libraries

Embedded Linux Kernel

Drivers

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Hardware

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-          As you see, Application runs on Linux OS so that is why we need Emulator on Windows. With Emulator, application uses none of the Windows resource but runs on emulated smart phone resource.

-          Linux OS will provide a certain degree of abstraction from Hardware layer.

·         What is the difference between Application and Widget?

Application will hold the entire screen once it is launched. Widget runs using only a part of the screen (similarly  windows applications on PC or any other shell)

·         What is dalvik?

This is a virtual machine developed by google.

·         State machine
      - Android app is a state machine

- By using  Java’s object oriented mechanism, all applications can be written based on a certain base classes such as Activities.