a downrigger is a unit to get your bait of choice to the bottom, (like a big hand reel) where the fish are.
when you get a strike your bait releases from the outrigger, then you frantically bring up the down rigger and fight the fish on your rod & reel, thats a quick quote but there are some legends on here and they will
run you thru it properly!
..cheers!..stevo!..