Redis is an in-memory key-value data store, meaning it stores data in RAM instead of on disk. This makes it much faster than traditional databases like MySQL or PostgreSQL, which rely on disk-based storage. Redis also offers a wide range of features, such as data structures, replication, and high availability. In comparison to other databases, Redis is a great choice for applications that require high performance and scalability. For example, it is often used for caching, real-time analytics, and gaming leaderboards.