All the pieces and how they work together!
Maintainer of Commerce Reports, Commerce Deploy, MojoCart
Co-maintainer of Drupal Commerce, Commerce Kickstart
Drupal Commerce is about as Drupal-y as they come, harnessing the power of the major and most used modules in the Drupal ecosystem.
Drupal Commerce uses the Entity API to the fullest, utilizing five different entities in total.
It extends core's entity API into a more unified structure, including CRUD operations. Entities in Drupal are a way to handle data and utilize the Field API (simply put.)
No custom code for displaying entities, everything is powered by Views.
Drupal hooks with a user interface. Setup conditions which react to events and perform specific actions. Drupal Commerce harnesses much of its functionality through Rules rather than standard hook implementations.
Last, but not least, Entity integration could not be completed without Field API.
Drupal Commerce isn't just Drupal-y because it utilizes other contributed projects, but because it is composed of ELEVEN sub-projects itself.
Decoupled design allows for complex implementation and ultimate flexibility.
Before diving in: there is Commerce Kickstart that provides a demo store and an opinionated installation of a Drupal Commerce site.
There are two installation options: demo, or no demo. The demo is great for learning Drupal Commerce and having a best-practices example. However, if you are going to build a Drupal Commerce site, use the no demo install
In my opinion the most integral entity in the Commerce system.
The product pricing module is an API that extends hooks provided by the Price module. It utilizes Rules to adjust the components of a price field to increase or decrease the total price amount
That was a lot. I mean a lot.
Commerce Kickstart provides a demo store installation complete with products, categories, blog, ad placements, and more.
Who should use Commerce Kickstart? Anyone who wants to skip weeks of configuration to build a commerce site on the Drupal Commerce framework.
It's opinionated and a great way to get started on your first project.
Commerce Deploy aims to simplify Drupal Commerce development for site builders and developers. Get started faster and cut the cruft of dependency gathering. The ideology behind Commerce Deploy is to provide enhancements to Drupal Commerce development without getting in the way.
It is a decoupled base distibution composed of several projects - so you can take the whole thing or the parts you want for your own distributions.
Currently in development, MojoCart plans to harness the power of Apps and provide a robust site builder Drupal Commerce experience powered by Panels.