Arduino is an open source hardware and software project, created with a simple aim in mind, to be as simple as possible. Arduino is not some hardware you should be afraid of. Arduino comes in a variety of flavors and sizes. It is used by artists, hackers, hobbyists, and professionals to easily design, prototype and experiment with electronics. Use it as brains for your robot, to build a new digital music instrument, or to make your house plant tweet you when it's dry. An Arduino contains a microchip, which is a very small computer that you can program. You can attach sensors to it so that it can measure conditions (like how much light there is in the room). It can control how other objects react to those conditions (room gets dark. LED turns on).