Redis is an in-memory database that can be used for both caching and session store scenarios, with applications storing data in the cache to serve future requests faster, typically with sub-millisecond latency, and session-oriented applications storing all session-related data either in main memory or a session store that doesn't lose data when the application goes down. A cache is designed to store frequently accessed data to reduce latency, while a session store is used to store user-specific data during an active session period, requiring high availability and durability. Redis Enterprise can be used for both use cases with proper architecture and design, ensuring data separation between sessions by using unique session IDs and storing data in separate key structures.