Mongo DB is a no-SQL database. It is a non-relational database system. It is easily scalable because the data is loosely coupled.
In the third release, we added a functionality to compress product images and to have realtime chat between users and admin.
In the second release, we added more features. Allowing users to give reviews about a product. Allowing admin to charge different shipping fee for each country and many more.
In the very first release, we build the basic E-commerce version where admin can add products and user can see them. Add them in carts and order them. We also added Stripe and PayPal payment methods.