Simple Electronics with the GPIO Pins
Up until now we have seen the Raspberry Pi communicate with the keyboard and mouse as input devices and the display as an output. The Raspberry Pi can communicate with a wide variety of peripherals – a fancy name for things you can add on – as well as electronic components like Light Emitting Diodes (LEDs) or switches. This is achieved by attaching devices through the pins on the top of the Raspberry Pi. These pins are called the General Purpose Input/ Output pins or GPIOs for short.