Short answers, pulled from the story.
Keith Baker created the Eberron setting after winning a 2002 competition with his entry Thrilling Tales of Swords and Sorcery. Bill Slavicsek officially named the world Eberron during collaborative work at Wizards of the Coast offices.
The official Eberron Campaign Setting hardback book arrived in June 2004 for the third edition of Dungeons & Dragons. That same year, the sourcebook won the Origins Award for Best Roleplaying Game Supplement.
Siberys forms the planetary rings surrounding the world known as Eberron while Khyber represents the underworld beneath the surface. Siberys broke into pieces and Eberron wrapped around both entities to stop Khyber from creating demons that plague the world today.
High-level magic including resurrection spells appears less common than in standard Dungeons & Dragons worlds while low-level magic pervades daily life through Dragonmarked Houses. Cities feature magical lanterns illuminating streets throughout urban centers and a continent-spanning lightning rail provides high-speed transportation powered by magic.
Warforged constructs emerged as living sentient beings composed of stone wood and metal during the Last War when House Cannith created these soldiers in magical creation forges. Kalashtar represent psionic humanoids formed from human monks possessed by good-aligned Quori spirits fleeing Dal Quor.