What is ActionDispatch?

Question

I have a fairly decent grasp on the basic Rails concepts like ActiveRecord, routing, migrations, etc. One thing I'm having a hard time understanding is ActionDispatch. I can't find a plain-English description (or really any description) of what it is. So what is it?

Answer 1

In one, short sentence: Action Dispatch routes requests to controllers. For the more detailed explanation, I would recommend reading "Action Dispatcher and Action Controller in Rails 4".