You would use it in conjunction with the concept of Services [0]. Services are essentially are a group of CRUD operations that can be exposed over various transports: HTTP(s), Websockets, etc.
You can use services with Feathers' Event Emitters [1] give you a service-level abstraction for sending data over websockets. If you want the full flexibility of using websockets directly-- by all means, do so! A common use case, however, is to send updates as service objects are created, updated, or deleted over websockets for real-time applications. You might take that updated record, insert it into your state management system (e.g., Redux), and then use your UI library (e.g., React) to repaint the user's screen. Feathers doesn't care what state management or UI library you use.