Also, is that like Quarts in the Spring Framework?
This isn't about threading, really. I'll explain it in terms of Rails's delayed_job because I'm not familiar with the details of Celery:
* Let's say I want to send an email, via the function Mailer.deliver_notice(email)
* With delayed_job, I turn this call into Mailer.delay.deliver_notice(email). This puts an entry into a Jobs table in the database that makes note of what I want to run, with all the details.
* In the background, I have a daemon running that checks the Jobs table every five seconds for jobs that need to be run. It uses the information in the table to execute the deliver_notice function.
* That's it.