A major difference between AC and DC fans are its connectors. AC fans either have a terminal connector or two wire cords while DC fans have no more than two wire connectors. 

 

AC Terminal Connectors

            

Terminal connectors are two metal prongs that protrude from the side of a fan. Terminals tend to be more convenient due not only its reduced need for soldering but also its versatility in its ability to switch between various fan cords.

Wire Cord: Wire cords convert a fan with terminal pins into wire connectors. When a fan needs to be replaced, simply remove the fan from the wire cord and replace it. This eliminates the need to solder replacement fans.

Power Plug Cord: A power plug cord allows a terminal connector fan to be powered through an electrical outlet. 

AC Wire Connectors

             Wire connectors, or leads, are two wires sticking out of the fan. Wire cords can be soldered onto a power source or a power cord. Soldering must take place every time a fan needs to be replaced. 

DC Connectors

             DC connectors come with 2-4 wires and in different colors. The red wire needs a positive voltage while the black wire needs a negative voltage. The third or fourth wire, which comes in either yellow or black, help control special functions of the fan like PWM.