This shows the pinout for the Raspberry Pi 4. It shows both the BOARD numbering scheme, and the BCM numbering scheme. You define which numbering scheme you want to use in your python program. You must start by importing the GPIO Library:
import RPi.GPIO as GPIO
Then, if you use setmode to define which numbering scheme you want:
will give you the Physical Pin numbering scheme.
If you use:
You will be using the BCM Numbering Scheme. I prefer the BOARD Scheme as it is much easier to keep track of. Hope this helps.