I am not sure what you are asking. First you say you are staying in a quad cabin, then you ask what a quad cabin is. How do you know you are in a quad cabin if you do not know what it is? At any rate, if your question is what is a quad cabin, it is a cabin that sleeps four. Usually two twin beds that can be made into a queen plus one of the following:
1) Two single beds that come out of the ceiling.
2) One single bed that comes out of the ceiling and a single fold out sleeper sofa.
3) A double sleeper sofa.
4) Three beds inside and a hammock on the balcony. Oops, sorry, you said you were in an inside cabin.
I hope this answers your question.
Now if you have two comp cruises and two 50% off vouchers, why don't you get two cabins that are next to each other? You might find that having two bathrooms (instead of one) plus the extra room has value.