Arduino is an open-source computer hardware and software company, project and user community that designs and manufactures kits for building digital devices and interactive objects that can sense and control the physical world.

Arduino is the name of a popular open electronic learning platform for teaching Physical Computing based around a set of open standards. Devices cost as little as $2.50 US. There are over 2 million YouTube videos on Arduino projects. An Arduino is programmed using a PC and a USB cable. Once an Arduino program is uploaded into a device it can be disconnected.

An Arduino microcontroller is open-sourced hardware with varying amounts of flash memory, pins, and features for performing functions such as reading analog signals and performing digital output. There are many Arduino boards available, such as the Arduino Uno, Leonardo, Mega, or SparkFun’s Redboard.

An Arduino is a popular brand of microcontroller. While created by the Arduino team initially they are open source so clones and offshoots can be manufactured by anyone. They provide a much lower barrier-to-entry than what existed previously to begin programming electronics. They are great at controlling servos, LEDs, motor controllers, reading sensors and more. Newer versions come with WiFi and Bluetooth capabilities. There is a large ecosystem of boards designed to plug directly into the top of an Arduino, such a board is called an Arduino Shield.