What is the difference between Redis and traditional relational databases?

Beginner

Answer

Aspect Redis Relational Database
Storage In-memory Disk-based
Data Model Key-value, NoSQL Relational tables
Schema Schema-less Fixed schema
ACID Limited ACID properties Full ACID compliance
Performance Extremely fast (microseconds) Slower (milliseconds)
Persistence Optional Always persistent
Query Language Commands SQL
Relationships No joins Complex relationships
Use Cases Caching, sessions, real-time Complex business logic