Locality Sensitive Hashing allows for quickly finding similar entries in large databases. It is a randomized algorithm that does not guarantee exact answers but provides a high probability of returning the correct or close answers. LSH reduces the dimensionality of high-dimensional data and does not rely on linearly searching the entire database. The document discusses how finding similar objects in large datasets is a challenge due to the massive amount of data and computational requirements, and introduces LSH as a method to address this challenge.