*** ### What is Caffeine cache? - A **high-performance caching library for Java**. - One fundamental difference between a [[Cache Vs Buffer | cache]] and a _Map_ is that a cache evicts stored items. - An **eviction policy decides which objects should be deleted** at any given time. This policy **directly affects the cache's hit rate** — a crucial characteristic of caching libraries. - Caffeine uses the _Window TinyLfu_ eviction policy, which provides a **near-optimal hit rate**. *** **References**: - [Introduction to Caffeine](https://www.baeldung.com/java-caching-caffeine)