How is redis different from RabbitMQ?

Question

Redis

I have long known about these technologies and it's time to feel them. There is no time to pinch both, but there is a desire to understand one well.
As far as I knew RabbitMQ is a queue server, and Redis is a key-value store. However, now I see redis is often used both as a queue and as well as pub/sub.
Therefore, the question is what is actually the difference between them and where to use what?

Answer 1

RabbitMQ is a full-fledged queue server that has "its own" database under the hood. Redis is a database over which a queue server can be built. It makes sense to build a queue server over Redis, IMHO, if a full-fledged server is not needed, and Redis is already used as a database.