Flexible Entity Manager
While OroCRM uses the Doctrine 2 Object Relational Mapper (ORM), the OroCRM core development team has extended standard Doctrine with a number of enhancements (working mostly within the systems provided by Doctrine) to implement a Flexible Entity System.
The Flexible Entity system offers an end-user with little to no development skill the ability to add new fields to objects, and have user interface elements for those fields in an entity's main editing form.
In other words, it's UI configurable CRUD. Not exactly rocket science in 2014, but a none-the-less important part of any CRM system. While a business could install a stock OroCRM system and get some value from it, the real value of a CRM is the customizations made for a specific business, or business type. The bet OroCRM the company is making is that companies will prefer working with OroCRM, or OroCRM based development teams to build a system they own vs. relying on a cloud provider's vision for what their CRM should be.
You can find the user interface for this section at
System -> Entities
While day-to-day users of an OroCRM application will spend little time here, I suspect OroCRM developers will become very familiar with this particular screen.