Android is an operating system for mobile phones and tablets, in much the same way that PCs run Microsoft Windows as their operating system. It's maintained by Google, and comes in a few different versions. At the time of writing, mobile phones run a variant of versions (1,1.5 Cupcake, 1.6 Donut, 2.0 Eclair, 2.3 Gingerbread, 3.x Honey Comb, 4.x Jelly Bean) of Android, while most new tablets run a variant of version 3.
