Spinning rod and reels test lbs

I’m looking at large spinning reels and rods for deep sea and I see conventional reels and rods that have a lot higher line lbs then I look at spinning reels and rods that are big and are extra heavy rods but are only rated for like 30 lbs test why is that? Is it a different measurement or something. I looked at the same rod one for conventional and the other for spinning the conventional was rated at 130 lbs and the spinning was 30 I don’t get it.