First, we need to choose what is called a Message Broker, required by Celery in order to send and receive messages. Here we will use RabbitMQ, which is feature-complete, stable, durable and easy to install. Moreover, it is the default broker so it does not require additional configuration
Check out how to install it for your particular system here. If you are using Mac OS X you can install it with homebrew (and if you want to install first homebrew… check this post):
Celery: Distributed Task Queue
Celery is an asynchronous task queue/job queue based on distributed message passing. It is focused on real-time operation, but supports scheduling as well.
The execution units, called tasks, are executed concurrently on a single or more worker servers using multiprocessing, Eventlet, or gevent. Tasks can execute asynchronously (in the background) or synchronously (wait until ready).