Celery is a Distributed Task Queue. What this means is that in the context of RabbitMQ and AMQP, it takes the entire AMQP model and shapes it; it folds only the best ideas from it into providing a world-class, production-grade background queue library for you to use.
Celery allows for swappable backends, and one of them is RabbitMQ, which we'll explore here.
Celery is mind-numbingly used almost everywhere in nearly every Python-based company or start-up to do background jobs; it's also used in big corporations, such as Mozilla; see more information at: https://github.com/celery/celery/wiki#companieswebsites-using-celery.
Hopefully, you're excited about exploring Celery as I am; I hope you'll be amazed at Celery's conciseness.