I am trying to learn nmap. I am running several host discovery commands. With the -PR, -PU, -PE, -PP, -PM, -PS, -PA. All with the -sn flag. I have Wireshark open and I see that every single command sends an ARP request and gets a ARP reply. All of the packets from each command are exactly the same down to the last bit. If this is the case what is the difference between each of those different flags ?

I am unable to find a solution for it. Can anyone please tell me the process and steps involved in it? enter image description here