Difference between sys_fan and pwr_fan?

[FelixTheHammer]

My new motherboard, a Gigabyte GA-970A-UD3P (http://www.newegg.com/Product/Product.aspx?Item=N82E16813128651&Tpk=ud3p) has one 3 and one 4-pin header labeled sys_fan and a 3-pin header labeled pwr_fan. What are the differences between sys and pwr fans and can I plug a case fan into a pwr_fan header?

 

[Phillip Corcoran]

SYS_FAN header is for a case fan.

PWR_FAN header is for PSU fan where applicable (ie some PSUs have external lead for the fan).
Do not use PWR_FAN header for anything else.