Arduino is composed of two major parts: the Arduino board, which is the piece of hardware you work on when you build your objects; and the Arduino 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 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 programs.
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.
The Arduino board is a small microcontroller board, which is a small circuit (the board) that contains a whole computer on a small chip (the microcontroller). This computer is at least a thousand times less powerful than the MacBook I’m using to write this, but it’s a lot cheaper and very useful to build interesting devices. Look at the Arduino board: you’ll see a black chip with 28 “legs”—that chip is ...