ADuCM360/CN0338 ADC readings

Hi everyone!

I am doing a demo of cn0338(gas measurement). I have an issue about how the adc works and what is the resolution rate or what is the af and fs constant mean. I am working on the readings of the measurements but I think they are not so accurate that is why I want to figure out the how the ADC works?  Does anyone know video or document about configuration the adc. Thank you for your reply.