Each of the Raspberry Pi GPIO pins can perform digital input and output. Digital simply means something is either fully on or fully off—there is no middle ground. We've been working with simple digital IO in previous chapters:
- Our LED was either on or off.
- Our button was either pressed (on) or non-pressed (off).
You will come across several interchangeable terms used to describe digital states, including the following:
- On = High = True = 1
- Off = Low = False = 0
Digital IO is a form of basic IO. Analog IO is another, so we will explore it next.
