How do MongoDB, Redis, and a vector index differ?
Practice this question- MongoDB stores application documents and canonical records where appropriate.
- Redis provides scoped caching/counters/queue backing.
- A vector index serves derived retrieval representations; none should silently replace authoritative claim-service truth.
Adapted from 13_AI.MD · “29.20 MERN and AI”. Code examples are study fragments. Difficulty and core labels are editorial estimates; version-specific behavior should be checked against your project.