Android is an operating system based on the Linux kernel, and designed primarily for touchscreen mobile devices such as smartphones and tablet computers . Initially developed by Android, Inc., which Google backed financially and later bought in 2005, Android was unveiled in 2007 along with the founding of the Open Handset Alliance: a consortium of hardware, software, and telecommunication companies devoted to advancing open standards for mobile devices.
Each version of Android since 1.5 has been developed with a specific codename. These codenames are chosen alphabetically, and have thus far all been dessert items (or, generically, sweet/sugary foods). Some codenames are associated with more than one version number, while others are limited to only a specific one, and the reason for this inconsistency is not currently known.
The naming typically appears to correspond to changes in the developer API levels, but this is not always true (example: 3.0 and 3.1 are both "Honeycomb" but they have different API levels). The following names are used for the currently existing Android releases.
Complete List of All Android OS
Note that versions 1.0 and 1.1 were not publicly named. However, Android 1.1 was internally referred to as "Petit-Four".
Below are the list of Android OS and their names:
• Android 1.5 Cupcake
• Android 1.6 Donut
• Android 2.0 Eclair
• Android 2.1 Eclair
• Android 2.2 (froyo) frozen yogurt
• Android 2.3 Gingerbread
• Android 3.0 Honeycomb
• Android 3.1 Honeycomb
• Android 3.2 Honeycomb
• Android 4.0 Ice Cream Sandwich
• Android 4.1 Jelly Bean
• Android 4.2 Jelly Bean
• Android 4.3 Jelly Bean
• Android 4.4 KitKat
• Android 5.0 Android Lollipop
• Android 5.1 Lollipop Update
• Android 6.0 Marshmallow
• Android 7.0 Nougat