Android was developed in 2003 in Palo Alto, California and was purchased by Google in 2005. It is an open-source operating system used on many types of devices including smartphones, tablets, TVs and more. Some key features of Android include access to millions of applications, an improved interface over previous mobile operating systems, and the ability to develop applications using Java and SDK tools. The operating system contains over 12 million lines of code written in languages like XML, C, Java and C++.