When to use Interface and Model in TypeScript / Angular2

Question

I recently watched a Tutorial on Angular 2 with TypeScript, but unsure when to use an Interface and when to use a Model to hold data structures.

Example of interface

Answer 1

Use Class instead of Interface that is what I discovered after all my research.

Why? A class alone is less code than a class-plus-interface. (anyway you may require a Class for data model)

Why? A class can act as an interface (use implements instead of extends).

Why? An interface-class can be a provider lookup token in Angular dependency injection.

from Angular Style Guide

Basically a Class can do all, what an Interface will do. So may never need to use an Interface.