The spell called "spiritual projection" or "astral projection" brings the caster to the Twisting Nether instead of the Shadowlands; and the Twisting Nether is also referred as "realm of ghosts". However, both planes don't appear to be related, as Outland is floating on the Twisting Nether, but the Shadowlands can be reached in Outland in The Burning Crusade.
World of Warcraft: Shadowlands marks the eighth major expansion pack for the storied MMO. Judging from a half-hour playing it at BlizzCon this year, it seems like a natural evolution of modern WoW that will run alongside the very-different WoW Classic experience for the foreseeable future. That said, the biggest change wasn't part of my hands-on demo—but don't worry, that won't stop me from geeking out about it in extreme detail.
Sometimes, the spirits roam the Shadowlands without resting. It can be because their resting place wasn't complete, because of a battle in their resting place or because of the corruption of their resting place. To bring eternal peace to the souls, it is needed to destroy the source of corruption or by making a ceremony with items such as [Tuskarr Ritual Object]. A spirit in the Shadowlands can, with enough power over other souls, tear a hole into the living world once they are strong enough. This is how Jin'do returned to Azeroth.
The experience curve is adjusted to make it faster than ever to prepare for the newest challenges, and each level along the way will provide more meaningful increases in progress and power. All expansion zones are getting more flexible, too; they'll be able* to scale to you and your friends while you level to 50, so it's easy to try a zone you've never played.