# Bloom Filters- An Intro

Bloom Filters are quite simply put space-efficient, probabilistic data structures which help answer the question of set membership. From a mathematical lens say that you need to verify whether an element *x *belongs to a set **A **, if the Bloom Filter as a data structure returns true for *x, what this means is that either x is definitely in the set A or it may not be in the set A. *An* *implication that follow from this is that Bloom Filters are quite efficient at preprocessing and filtering out large lists, for further detailed set operations such as joins and intersections.