Android versions

The version history of the Android mobile operating system began with the release of the Android beta in November 2007. The first commercial version, Android 1.0, was released in September 2008. Android is under ongoing development by Google and the Open Handset Alliance (OHA), and has seen a number of updates to its base operating system since its initial release.

Since April 2009, Android versions have been developed under a confectionery-themed code name and released according to alphabetical order: Cupcake (1.5), Donut (1.6), Eclair (2.0–2.1), Froyo (2.2–2.2.3), Gingerbread (2.3–2.3.7), Honeycomb (3.0–3.2.6), Ice Cream Sandwich (4.0–4.0.4), Jelly Bean (4.1–4.3), and KitKat (4.4). On 3 September 2013, Google announced that 1 billion activated devices now use the Android OS worldwide. The most recent major Android update was KitKat 4.4, which was released to commercial devices on 22 November 2013, via an OTA update.

1.0- Android

1.1-Android

1.5-Cupcake

1.6-Donut

2.1-Eclair

2.2-Froyo

2.3-Gingerbread

3.0-Honeycomb

4.0-Ice Cream Sandwich 

4.1-Jelly Bean----------level 16

4.2-Jelly Bean----------level 17

4.3-Jelly Bean----------level 18

4.4-KitKat

5.0 Lollipop

5.1 Lollipop

6.0 Marshmallow

The new things about the Android is - from Android version 4.4 kitkat to its next versions will come through "OTA" (Over The Air). Means you have no need to go to your mobile store/care to update your device, you can get the update through the Air.

Suggestions:- 

1.To update your device, Always use WiFi connection.

2.When you are going to update your device, check that your phone is at least 90% charge.

3.Always re-start your phone after successful update.