Android is an open-source, Linux-based operating system used primarily in mobile devices like smartphones and tablets. It was developed by Android Inc. before being acquired by Google. Android allows for over 400,000 apps and has gone through many versions from Cupcake to the current Android 11. Developers can create Android apps using Java, Kotlin, and C++ through the Android software development kit to take advantage of Android's customizable operating system and large user base in the global app marketplace.