> Why is these data structures called "filters" rather than hashes. I would guess because they are probabilistic data-structures which are information-lossy. B

> Why is these data structures called "filters" rather than hashes. I would guess because they are probabilistic data-structures which are information-lossy. Bloom Filters and Cuckoo Filters aren't guaranteed to give you a correct result and they cannot retrieve the original input. Cuckoo Filters of course take the name from Cuckoo hashing.