As a beginner, need best practices for basic scenarios

Question 1:

When to use POJO and when to use Ember objects?

Question 2: Cloning

Assume i have a complex model for a template i.e, set through model hook of route.

How can i clone the entire model in the way that changes in model should not reflect on cloned model.

I gone through Ember.Copyable, but i am not sure how to achieve this.

Could you please provide any examples for this.