wheel load rating

What is wheel load rating and why is it important for towing? I recently found a good deal on some new wheels but wanted to make sure I'm making an informed decision before buying. Someone mentioned wheel load rating the other day but I cant find that post. Any way, can someone help me...

Well my Gladiator sport S with max tow finally came in. I told the dealer I was looking for some Rubicon tire and wheels. He told me to make sure not to use the ones off a Wrangler because the rating weren't high enough for the Gladiator. Does anyone know what the load rating is on the Gladiator...