From what I've read and understand MVCS (Model-View-Controller-Store) is a design pattern that lets you do the following:
View - Application view, what the user will see.
Controllers - Manages the views and calls the models.
Model - Business logic.
Stores - Calls to db for CRUD operations retrieving and putting data.
Now where should I put the domain in this design? By domain, I mean the actual classes that represents the objects from db for example a user. Should they be inside the model or in a different layer?