Data-centric functionality

Data-centric is the term used to describe the way Appian encourages to model all the application specific data in Records and reports.
Instead of having long-running processes(as in the legacy portal version), the application data model is organized around Records and reports. The records and reports are the data of your application, and you can take action on the records(say using related actions), or drill into your data using reports.
This frees Appian from launching process instances for everything (which was the case in legacy portal version of Appian). This reduces the need for developing processes for each and every functionality, and processes you design tend to be lightweight and short-lived which is good from a performance perspective.
Another advantage is that you can control what data item (record item) is visible to which user by Appian's security model based on groups and security roles.
For more details on the data-centric approach, go through the Appian academy courses - especially the Analyst course.

Thank you Chetan