DSpace 7.0, released in August 2021, was the largest release in the history of DSpace and required multiple years of development.  In addition to the resources here, Lyrasis (the organizational home for DSpace) maintains DSpace technical and user documentation in its wiki: Lyrasis DSpace 7 Documentation

DSpace 7 represents a major change from DSpace 6. It includes:

• A new User Interface based on Angular (to replace XMLUI and JSPUI)

• A refactored/enhanced REST API (using modern REST best practices)

• Redesigned submissions and workflows 

• A new Configurable Entities object model, which allows for the creation of new "typed" Items, and storing relationships between Items

• Improved compliance with web accessibility guidelines

Functional Overview of DSpace

The Functional Overview of DSpace provided by Lyrasis (the development home of DSpace), provides a good introduction to the capabilities of the system, and introduces terminology important to using DSpace.