What are the differences between OS 1.3 and OS 2.04?

[DoomMaster]

I have just bought another Amiga 2000HD from eBay.  It has the ECS Chip Set and the Kickstart 2.04 ROM.  The Amiga 2000HD that I have now has Kickstart / Workbench 1.3.  What are the differences between these two Amiga OSs ?  What else do I need to record CD-Rs on my new Amiga 2000HD using OS 2.04?  Thanks     :-D

[DoomMaster]

To Thomas:

Most of the CD recording (burning) software runs on OS 2.04.  I already have a Yamaha 4416S CD-RW drive.  It is ranked in the top 4 CD-RW drives on the MakeCD web site.  BurnIt also highly recommends the Yamaha 4416S CD-RW drive.  Do I need anything else besides a Processor Accelerator card?  Will 9 megs of memory be enough?  I do not want to go beyond the Amiga 2000HDs 9 megs of ram barrier (1 meg Chip and 8 megs Fast).  To do so will make the system highly unstable.  If I can run powerful animation software on 9 megs then surely a CD burner program requires much less memory.