What is "arduino"

"Arduino is an open-source electronic prototyping platform based on flexible and easy-to-use hardware and software. It is aimed at artists, designers, hobbyists, and anyone interested in creating interactive objects or environments." from Adian.

Arduino refers to both hardware (single micro-controller embedded) and software (a minimized IDE based on Processing IDE ), which makes prototyping hardware simple and attractive to people with little or no programming experience.

Arduino coding is simplified by the Wiring language, auxiliary functions and code manipulation behind the scenes (via AVR Libc and avrdude). Advanced users can use the preferred C/C++ IDE, alternatively.

"Arduino Uno is an Atmega328-based microcontroller board (leaflet). It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a 16 Mhz ceramic resonator, a USB connection, a power connector, an ICSP pumphead, and a reset button; it contains all the necessary to support the microcontroller. Simply connect it to a computer with a USB cable or connect it with an AC to DC adapter or battery to get started." More details on the Arduino Wiki

Arduino is open-source, which means anyone can manufacture a plate compatible and official website offers detailed instructions.