Teensy 3.2 Pins - BleepLabs/Arduino-Light-And-Sound GitHub Wiki

Different pins on the Teensy can do different things.

An analog pin can read analog voltages while a digital pin can only read on (3.3V) and off (0V aka ground).
PWM pins can be used to vary the intensity of LEDs while a digital pin can only write on and off.
Touch sensing pins can read how hard you re pressing on a piece of wire or other touch contact attached to them.
More pins can be added using multiplexers which we'll talk about later on.