Android is an open source operating system based on Linux. It was originally developed by Android Inc. and later acquired by Google. Android provides a framework for building apps using Java and runs them on a virtual machine called Dalvik, which was optimized for mobile devices. The Android software stack consists of apps running on top of libraries, an application framework, and the Dalvik virtual machine running on the Linux kernel.

1. ANDROID
ANDROID

2. INTRODUCTION TO ANDROID
• Android is an open source and Linux-based operating system. It was first
introduced on Nov 5, 2007. It was originally developed by Android Inc.
and subsequently purchased by Google.
• Basically, Android is thought of as a mobile operating system. But it is
not limited to mobile only. It is currently used in various devices such as
mobiles, tablets, televisions etc.
• Android provides a rich application framework that allows us to build
innovative apps and games for mobile devices in a Java language
environment.
• The Android open-source software stack consists of Java applications
running on a Java-based, object-oriented application framework on top
of Java core libraries running on a Dalvik virtual machine featuring JIT
compilation.

3. Why?
• There are so many reasons you should choose Android platform for mobile application development.
• Zero development cost
The development tools like Android SDK, JDK, and Eclipse IDE etc. are free to download for the
android mobile application development. Also Google charge a small fee $25, to distribute your
mobile app on the Android Market.
• Open Source
The Android OS is an open-source platform based on the Linux kernel and multiple open-source
libraries. In this way developers are free to contribute or extend the platform as necessary for building
mobile apps which run on Android devices.
• Multi-Platform Support
In market, there are a wide range of hardware devices powered by the Android OS, including many
different phones and tablet. Even development of android mobile apps can occur on Windows, Mac
OS or Linux.
• Multi-Carrier Support
World wide a large number of telecom carriers like Airtel, Vodafone, Idea Cellular, AT&T Mobility, BSNL
etc. are supporting Android powered phones.
• Open Distribution Model
Android Market place (Google Play store) has very few restrictions on the content or functionality of
an android app. So the developer can distribute theirs app through Google Play store and as well
other distribution channels like Amazon’s app store.

4. History of Android
• Initially, Andy Rubin founded Android Incorporation in Palo
Alto, California, United States in October, 2003.
• In 17th August 2005, Google acquired android Incorporation.
Since then, it is in the subsidiary of Google Incorporation.
• The key employees of Android Incorporation are Andy Rubin,
Rich Miner, Chris White and Nick Sears.
• Originally intended for camera but shifted to smart phones
later because of low market for camera only.
• Android is the nickname of Andy Rubin given by co-workers
because of his love to robots.
• In 2007, Google announces the development of android OS.
• In 2008, HTC launched the first android mobile.

5. Android Versions

6. Versions Name Release Date What’s New?
Android 1.0 (September 23, 2008) HTC Dream
Android 1.1 (February 9, 2009) unofficially called Petit Four
Android 1.5 Cupcake (April 27, 2009) Samsung Galaxy
Android 1.6 Donut (September 15, 2009) Dell Streak
Android 2.0-2.1 Eclair (October 26, 2009) Motorola Droid( text-to-
speech support)
Android 2.2 Froyo (May 20, 2010) Google’s Nexus (Wi-Fi mobile
hotspot)
Android 2.3 Gingerbread (December 6, 2010) Nexus S( voice input
capability,selfie)
Android 3.0 Honeycomb (February 22, 2011) only for tablets and mobile
devices with larger screens
Android 4.0 Ice Cream
Sandwich
(October 18, 2011) face Unlock,swipe gestures to
dismiss notifications

7. Versions Name Release Date What’s New?
Android 4.1 Jelly Bean (July 9, 2012) Nexus 7(support emoji and
screensavers )
Android 4.4 KitKat (October 31, 2013) Google’s Nexus 5
Android 5.0 Lollipop (November 12, 2014) Google’s Nexus 6 and Nexus
9 tablets(Android devices’
battery life with a Doze
mode)
Android 6.0 Marshmallow (October 5, 2015) Google’s Nexus 6P and Nexus
5X(smartphone with
biometric)
Android 7.0 Nougat (August 22, 2016) Pixel, and Pixel XL, and LG
V20(split-screen and fast
switching between apps)
Android 8.0 Oreo (August 21, 2017) autofill APIs(better managing
the passwords and fill data)

8. Versions Name Release Date What’s New?
Android 9.0 Pie (August 6, 2018) When swiped up, it brings
the apps used recently, a
search bar and suggestions
of five apps at the bottom.
Android 10 (September 3, 2019) support for the upcoming
foldable smartphones with
flexible displays.

9. Android Architecture
• Linux kernel
• Native libraries (middleware)
• Android Runtime
• Application Framework
• Applications

11. Linux kernel
• It is the heart of android architecture that exists at the root of
android architecture. Linux kernel is responsible for device
drivers, power management, memory management, device
management and resource access.

12. Native Libraries
• On the top of linux kernel, their are Native libraries such as WebKit, OpenGL,
FreeType, SQLite, Media, C runtime library (libc) etc.
• The WebKit library is responsible for browser support, SQLite is for database,
FreeType for font support, Media for playing and recording audio and video
formats.

13. Android Runtime
• In android runtime, there are core libraries and DVM (Dalvik Virtual Machine)
which is responsible to run android application. DVM is like JVM but it is
optimized for mobile devices. It consumes less memory and provides fast
performance.

14. Android Framework
• On the top of Native libraries and android runtime, there is android framework.
Android framework includes Android API's such as UI (User Interface),
telephony, resources, locations, Content Providers (data) and package
managers. It provides a lot of classes and interfaces for android application
development

15. Applications
• On the top of android framework, there are applications. All applications such
as home, contact, settings, games, browsers are using android framework
that uses android runtime and libraries. Android runtime and native libraries
are using linux kernal.

16. Installation and setup

17. Requirements
Windows requirements
• Microsoft Windows 7/8/10 (32-bit or 64-bit)
• 3 GB RAM minimum, 8 GB RAM recommended (plus 1 GB for the Android Emulator)
• 2 GB of available disk space minimum, 4 GB recommended (500 MB for IDE plus 1.5 GB for Android SDK and emulator system
image)
• 1280 x 800 minimum screen resolution
Mac OS requirements
• Mac OS X 10.10 (Yosemite) or higher, up to 10.13 (High Sierra)
• 3 GB RAM minimum, 8 GB RAM recommended (plus 1 GB for the Android Emulator)
• 2 GB of available disk space minimum, 4 GB recommended (500 MB for IDE plus 1.5 GB for Android SDK and emulator system
image)
• 1280 x 800 minimum screen resolution
Linux OS requirements
• GNOME or KDE desktop. Tested on Ubuntu 14.04 LTS, Trusty Tahr (64-bit distribution capable of running 32-bit applications)
• 64-bit distribution capable of running 32-bit applications
• GNU C Library (glibc) 2.19 or later
• 3 GB RAM minimum, 8 GB RAM recommended (plus 1 GB for the Android Emulator)
• 2 GB of available disk space minimum, 4 GB recommended (500 MB for IDE plus 1.5 GB for Android SDK and emulator system
image)
• 1280 x 800 minimum screen resolution

18. Download Android Studio
Link to download android studio:
• https://developer.android.com/studio/index.html

19. Download Android Studio SDK
Link to download android studio SDK:
• https://developer.android.com/studio#downloads

20. Installing Android Studio on 64-bit Windows 10

26. Running Android Studio

36. Dalvik Virtual Machine

37. Runtime Environment
• Runtime Environment consists of software instructions(generated
from the code) that are used while executing the programming.
JVM is the component that is used to convert bytecode into
machine code in orde
Why is a Virtual Machine need to run any Application?
• A Virtual Machine isolates the execution of the program from the
OS. Thus protecting malicious code from affecting the system files.
• Virtual Machines execute code independent of the CPU
architecturer to run Java-based programs.

38. Android DVM

39. Why Android uses DVM and not JVM?
• Mobile Environment is not as powerful as your computer
systems(majorly). There are battery and ram constraints. DVM
was specifically optimized in order to run on Android.
• JVM uses a Stack-based model -> Stack-based Virtual
Machines have the memory structure of the type Stack.
DM uses a Register based model -> Register-based uses
registers of the CPU to store the operands. So along with the
operands, their address is also stored.

40. APK File
• An Android Package Kit (APK for short) is the package file format used by
the Android operating system for distribution and installation of mobile apps. Just
like Windows (PC) systems use an .exe file for installing software, the APK does
the same for Android.
• When you download an APK online, you're essentially getting an app.
• Typically, users never see APK files because Android handles app installation in
the background via Google Play or another app distribution platform. However,
there are many websites that offer direct APK file download for Android users
who want to install apps manually themselves. In this case, you should be careful
that you trust the source of the APK file, because malware can be distributed in
APK files