What is Morgoths Ring?

[Anamatar IV]

Ive seen a 2nd type I guess of the Silmarillion called Morgoths Ring. What is it? It has basically the same chapters. Why a different book? Is it like the "cut scenes" from the silmarillion?

[Maedhros]

I think that the preface of the book would help you understand what it is about:
The Silmarillion, foundation of the imagined world of J. R. R. Tolkien, was as is well known never completed, never brought to a final form after the writing of The Lord of the Rings: the work is known from the text published posthumously in 1977, a construction from the narratives that existed, not a completion.
In Morgoth's Ring, the first of two companion volumes, Christopher Tolkien describes and documents the later history of The Silmarillion, from the time when his father turned again to 'the Matter of the Elder Days' after The Lord of the Rings was at last achieved. The text of the Annals of Aman, the 'Blessed Land' in the far West, is given in full; while in writings hitherto unknown is seen the nature of the problems that J. R. R. Tolkien explored in his later years, as new and radical ideas, portending upheaval in the old narratives, emerged at the heart of the mythology, and as the destinies of Men and Elves, mortals and immortals, became of central significance, together with a vastly enlarged perception of the evil of Melkor, the Shadow upon Arda. Among these writings a central place is given to the Athrabeth Finrod ah Andreth, in which the Elvish King of Nargothrond debates with the 'wise-woman' Andreth the injustice of human mortality.

[Mithlond]

Morgoth's Ring is book 10 of The History of Middle-earth. It has alot of info in it that is not found in the Silmarillion (such as earlier drafts of Silm chapters and later writings by Tolkien written after the texts in the published Silm), as does the rest of the HoMe series.

EDIT: Okay, Maedhros beat me. :)

[gate7ole]

I also give from the preface a very important reasoning for the name of the book (and the comparison between Morgoth's and Sauron's dominion):
For this reason I have chosen Morgoth's Ring as the title of this book. It derives from a passage in my father's essay, in which he contrasted the nature of Sauron's power, concentrated in the One Ring, with that of Morgoth's, enormously greater, but dispersed or disseminated into the very matter of Arda: 'the whole of Middle-Earth was Morgoth's Ring.