ARP && ARP spoofing

ARP 

(Adress Resolution Protocol)

What is ARP? 

Arp is a layer 2 protocol used to map MAC addresses to IP addresses.

What is ARP spoofing and how its works?

In computer networks, an Attacker can create fake arp packets and sends those packets into Local Network.
After that, network traffic related to the targeted host will send to the attacker host. This is an example of a Man in the Middle attack (MITM). So how its work actually, when the attacker sent those arp packets? 
Result of these packets being sent, the attacker deceives the targeted host by showing itself to be the router and at the same time attacker deceives the router by showing itself to be the targeted host.

If you want to try it you can use Ettercap: About « Ettercap (ettercap-project.org).

My basic arp spoofing code on GitHub written with python: JM00NJ/ARP-spoofing: ARP spoofing || Packet capturing (github.com)

Do not use these without the consent of the device owner or network owner.