UDF revisions: What are stream files and real time files?

UDF/UDFs 2.00: Stream files.
2.01 has real time files.
Alright, so what is that?

According to the documentation:

  • Real time files require a minimum speed.
  • Stream files are for DVD recording.

But our Sharp DV-RW250 supports DVD recording on UDF 2.00 (VR mode) and 1.02 (restricted but compatible DVD-Video format).

So didn’t UDF 1.02 already support stream files and real-time files? What exactly was changed?