Arduino is an open-source electronics platform based on easy-to-use hardware and software. It consists of both a physical programmable circuit board (often referred to as a microcontroller) and a piece of software, or IDE (Integrated Development Environment). Arduino boards are able to read inputs such as light on a sensor, a finger on a button, or a Twitter message, and turn it into an output such as activating a motor, turning on an LED, publishing something online, or sending a message. The boards are equipped with sets of digital and analog input/output (I/O) pins that may be interfaced to various expansion boards (shields) and other circuits. The boards feature serial communications interfaces, including Universal Serial Bus (USB) on some models, which are also used for loading programs. Most Arduino boards consist of an Atmel 8-bit AVR microcontroller with varying amounts of flash memory, pins, and features. The Arduino hardware and software was designed for artists, designers, hobbyists, hackers, newbies, and anyone interested in creating interactive objects or environments. The platform is widely used for building electronics projects, from everyday objects to complex scientific instruments. The Arduino community has gathered around this open-source platform, and their contributions have added up to an incredible amount of accessible knowledge that can be of great help to novices and experts alike.