Bloom Filter is a §202109071202 Probabilistic Data Structures that is extremely space efficient. Usually used to check if an element is present in a set of data or not.
There might be some False Positive results — which mean, the filter will tell us that the given element is already exists, but it's not. But it's guaranteed to not having any False Negative — it never say an element does not exists, when it's actually exists.
It can represent a set with really large number of elements. And delete an element from the filter is not possible as it might cause the deletion of other elements as well.