Introduction

Arduino is composed of two major parts: an Arduino board, which is the piece of hardware you work on when you build your objects; and the Arduino Integrated Development Environment, or IDE, the piece of software you run on your computer. You use the IDE to create a sketch (a little computer program) that you upload to the Arduino board. The sketch tells the board what to do.

Not too long ago, working on hardware meant building circuits from scratch, using hundreds of different components with strange names like resistor, capacitor, inductor, transistor, and so on. Every circuit was wired to do one specific application, and making changes to the circuit required you to cut wires, solder connections, and more.

With the appearance of digital technologies and microprocessors, these functions, which were once implemented with wires, were replaced by software. Software is easier to modify than hardware. With a few keypresses, you can radically change the logic of a device and try two or three versions in the same amount of time that it would take you to solder a couple of resistors.