Arduino Board employs a 10-bit analog-to-digital converter, which means (for the default) that an Analog Input channel reads a voltage between 0 and 5 V and slices that range into pieces.
The tutorial will focus on getting you up and running with Arduino quickly, so that you will understand the basic procedures for working with your ESP32 (specifically Adafruit's Huzzah32) and the ...
There was a time when building electronics and building software were two distinct activities. These days, almost any significant electronic project will use a CPU somewhere, or — at least — could.