Android is a mobile operating system based on a modified version of the Linux kernel and other open-source software, designed primarily for touchscreen mobile devices such as smartphones and tablets. It was developed by the Open Handset Alliance, led by Google, and other companies.

History

Android was unveiled in 2007, with the first commercial Android device, the HTC Dream, being launched in September 2008. It has gone through multiple major releases since then, with the current latest version being Android 12.

Features

Android provides a rich user experience that’s optimized for apps running on a range of hardware from phones and tablets to watches and televisions.

• App-centric: Android gives you a single application model that lets you deploy your apps broadly to hundreds of millions of users across a wide range of devices.
• Multi-tasking: The user can jump from one task to another and same time various applications can run simultaneously.
• Widgets: Widgets are resizable, so users can expand them to show more content or shrink them to save space.
• Multi-Language Support: It supports single-direction and bi-directional text.
• GCM (Google Cloud Messaging): Android provides a standard mechanism that allows third-party apps to use cloud-based services for push notifications.

Android Architecture

Android’s architecture is divided into five layers:

1. Linux Kernel: This provides a level of abstraction between the device hardware and it contains all the essential hardware drivers like camera, keypad, display, etc.
2. Libraries: These contain a set of instructions that guide the device’s response to different types of data.
3. Android Runtime: This includes core libraries and the Dalvik Virtual Machine.
4. Application Framework: This exposes the various capabilities of the Android OS to application developers so they can make use of them in their applications.
5. Applications: This is the topmost layer of Android architecture and it includes your app code and third-party apps.

Android Versions

1. Android 1.0 – No codename – API Level 1
2. Android 1.1 – Petit Four – API Level 2
3. Android 1.5 – Cupcake – API Level 3
4. Android 1.6 – Donut – API Level 4
5. Android 2.0 – 2.1 – Eclair – API Level 5 – 7
6. Android 2.2 – Froyo – API Level 8
7. Android 2.3 – Gingerbread – API Level 9 – 10
8. Android 3.0 – 3.2 – Honeycomb – API Level 11 – 13
9. Android 4.0 – Ice Cream Sandwich – API Level 14 – 15
10. Android 4.1 – 4.3 – Jelly Bean – API Level 16 – 18
11. Android 4.4 – KitKat – API Level 19 – 20
12. Android 5.0 – 5.1 – Lollipop – API Level 21 – 22
13. Android 6.0 – Marshmallow – API Level 23
14. Android 7.0 – 7.1 – Nougat – API Level 24 – 25
15. Android 8.0 – 8.1 – Oreo – API Level 26 – 27
16. Android 9.0 – Pie – API Level 28
17. Android 10.0 – Quince Tart – API Level 29
18. Android 11.0 – Red Velvet Cake – API Level 30
19. Android 12.0 – Snow Cone – API Level 31 – 32
20. Android 13.0 – Tiramisu – API Level 33
21. Android 14.0 – Upside Down Cake – API Level 34