What does "High Head" mean?

[bon_jon11]

Well I am looking to buy a pump for my new refugium but I am not sure on what size because of a few things. First I read that high head, then I assume it means how high the water can pump at that gph. If this means that than I was on the right track. Well I am trying to find a pump able to pump water 3.5 ft high to the main tank from the refugium. Its the "Quiet One Pump" and I found that it pumps about 230 gph at 3.5 ft. But what I wonder about is that I am using a hagen 402(270gph) for my sump to my refugium ( I am aware that bends take a lot of power away and powerheads are relatively weak for this kind of use) and if I get the other pump and use that I was wondering if the power of the two will work together. Both the sump and the refugium are on the ground sitting next to each other and will be about 12 inches away from each other with 3 bends all in all. I am hoping that the space (12inch.) will balance out with the power of the other pump so they cooperate. They are in the same area of power hopefully. But if the Quiet One Pump isnt what I think it is Ill be in trouble, so I need all the help I can get. Botton line, does the "hh" mean the amount of ft it can pump vertically and will both the pump be okay with each other? Please help everybody!! If it Helps Quiet One Pump 1200 and Hagen 402. If anyone has any suggestions on a better pump that will work well with the 402 please list. It has to pump 3.5 ft and has to match up with the 402's power. Sorry so long plp!