Yes, that's correct. Ordinal NFTs are indeed unique in that each one is typically a "1 of 1," meaning there is only one of each unique token. On the other hand, Stacks NFTs allow for the creator to determine the collection sizes, meaning that a creator can choose to have multiple copies or editions of a particular NFT within a collection. This could be, for example, a set of 10 or 100 editions of a specific piece of digital artwork. The flexibility in collection sizes is a key distinction between ordinal NFTs and stacks NFTs.