The new File Storage database supports storing, uploading, downloading, and accessing files related to records in Dataverse. These are the files that can stored in dedicated File and Image columns in Dataverse or as Attachments uploaded against Notes.
For an overview of files and images, it might be a good idea to check out the official Microsoft documentation so you get familiar with File and Image types if you haven’t done so yet:
NOTE: 2.6.x and 3.6.x versions of FakeXrmEasy add support for File columns. Image column support will be added in the next release.