What is a cardbox/moneybox

Yes, it's a place for guests or the bride and groom to drop envelopes in.

I like the idea as a guest because I always destroy or lose the card. As a bride, I think it's a good idea because you can store all of your cards in one place.

There are so many different variations that you can find one that fits your weddings style. I've seen mailboxes, birdcages, treasure chest looking boxes, etc.