Wonder about how do cpa companies tracking us while doing their offers

Hello guys ,
Can anyone expert here explain to me how cpa websites track us while we're doing their offers, I means what do they use for that

It's pretty straightforward, your tracking link send data back and forth to the ad server, than the server will exclude zones which dont provide conversions to your offer and will focus on the zones which do generate conversions for your offer. It's not instant as you may know the more data you gather in the process the more precious can the algorithm determine which zones to focus on or to exclude.