Mount another application

mount is used to mount another application (basically rack application) or rails engines to be used within the current application

syntax:

mount SomeRackApp, at: "some_route"

Now you can access above mounted application using route helper some_rack_app_path or some_rack_app_url.

But if you want to rename this helper name you can do it as:

mount SomeRackApp, at: "some_route", as: :myapp

This will generate the myapp_path and myapp_url helpers which can be used to navigate to this mounted app.