Gaming Loyalty Programs - Total Rewards Offers vs $0 Comps?

Hey.... I am a new TR member and I've been searching around for some answers.

I've started receiving "offers" for 2 free nights twice/month for AC casinos (I live nearby). I also see that when i go to make a reservation, the $0 rates.

I want to know what is the difference between using an offer and $0 rate comp? The offers seem to come every month, so I don't mind using them all up or just letting them expire. But I am uncertain of the $0 comps... do they expire? Do they use my rewards credits? Basically, what is the difference between these two types of incentives and which ones should I use if I have the option to use both?

On an unrelated note... I have XXX (Let's say 800) amount of rewards credit... what can i do with it? The Harrah's website isn't as helpful as I'd like.

Thanks in advance!

From my experience (with both ac and las) if the dates you pick exactly match the offer, the room comes up "free", if they don't, they are still giving you the room free, but it is then usually noted "comp". In both cases the price to you is $0.00.
If you make the booking directly on the internet, and you meet all the conditions of the promo, for the "free" offer, a special symbol will appear next to the offer [I]after the booking is made. In the "comp" case the symbol doesn't appear, so it is possible to make more booking than noted in the offer.]
If you have 800 reward credits = $8.00, you can apply this to purchase most items in any of Harrah's casinos. If you had 80,000, say, this is equivalent to $800, the ac casinos, for the past several months were able to convert this into CASH on a 2:1 ratio on different dates in different casinos, there was a minimum and maximum amount, but I don't remember the numbers off-hand.
PS: They don't deduct from your reward credits for the free room offers. [Ballys AC had a 1:1 redemption offer about a year ago.]

Thank nrr! I guess I'm asking that if I have Free room offers, and I have $0 Comps (via the reservation link).... which method is better to use?

Thank nrr! I guess I'm asking that if I have Free room offers, and I have $0 Comps (via the reservation link).... which method is better to use?
I don't understand the question. The advantage of using the $0 comp offer, is that you can use it more than once.