1Active Job is a framework for declaring jobs and making them run on a variety of 2queuing backends. These jobs can be everything from regularly scheduled 3clean-ups, to billing charges, to mailings. Anything that can be chopped up into 4small units of work and run in parallel, really. 5 6It also serves as the backend for Action Mailer's #deliver_later functionality 7that makes it easy to turn any mailing into a job for running later. That's one 8of the most common jobs in a modern web application: sending emails outside of 9the request-response cycle, so the user doesn't have to wait on it. 10 11The main point is to ensure that all Rails apps will have a job infrastructure 12in place, even if it's in the form of an "immediate runner". We can then have 13framework features and other gems build on top of that, without having to worry 14about API differences between Delayed Job and Resque. Picking your queuing 15backend becomes more of an operational concern, then. And you'll be able to 16switch between them without having to rewrite your jobs. 17