KitKat is the dessert-themed Android codename for the 4.4 update of the open source Android mobile operating system. 
KitKat debuted in November 2013 as the successor to the “Jelly Bean” Android releases.
The Android 4.4 update was widely expected to carry the Key Lime Pie codename, but Google instead decided to go with the iconic candy bar for the new update’s codename.
Google first had to get permission to use the KitKat name from the Nestle. Nestle also released a limited edition KitKat bar with Android-decorated packaging in conjunction with the new mobile OS release.
KitKat follows a number of earlier updates for Android, including Cupcake (v1.5), Donut (v1.6), Eclair (v2.0), FroYo (v2.2), Gingerbread (v2.3), Honeycomb (v3.0), Ice Cream Sandwich (v4.0) and Jelly Bean (v4.1, v4.2 and v4.3). The follow-up to KitKat is expected to carry the codename “Lemon Meringue.”
See also “An Introduction to Mobile Devices” in the Quick Reference section of Webopedia.
