What is Redis Stack and what does it add to vanilla Redis?

Redis Stack is a Redis distribution that bundles the core Redis server with several powerful modules: RedisJSON — native JSON document storage with path-based queries using JSONPath syntax, eliminating the need to serialize/deserialize JSON strings. RediSearch — a full-text search engine with secondary indexing, enabling SQL-like queries and full-text search on Redis data without scanning all keys. RedisBloom — probabilistic data structures (Bloom filters, Cuckoo filters, Count-Min sketch, Top-K). RedisTimeSeries — optimized storage for time-series data with downsampling, aggregation, and retention rules. RedisGraph (deprecated in favor of FalkorDB) — a graph database using the Cypher query language. Redis Stack is available as a Docker image or self-managed download, and Redis Cloud supports it. It positions Redis as a multi-model database for use cases beyond simple key-value caching.