Jay Miller checks for a record:
A bloom filter is a small, probabilistic data structure designed to answer one question: “Have I seen this item before?” It provides two potential answers: Absolutely Not, and Probably.
You may think that 100% Yes or No would be better but here’s the thing, probably is really fast and you’re really concerned about the Absolutely Not’s taking up unnecessary connections.
The article speaks to Aiven’s implementation of a Bloom filter in Valkey, but does get into some neat details on bloom filters in general. And if you want to go further down that route, Paul White explains how SQL Server uses Bloom filters.