What are the fan connectors on my GPU good for?

[TheOneAndOnlyEcon]

So i just ordered the asus strix 1080ti and i saw that there are 2 fan connectors. What do i use them for? if i plug my can fases into the gpu, will their speed get regulated by the gpu??(i have 4 pin case fans, if that matters) If not, what are they good for? stick my fans into the mbo or into the gpu???

 

[CountMike]

ASUS FanConnect II equips with hybrid controlled fan headers for optimal system cooling.