• There are four difficulties consisting of Normal (50-60), Heroic (60), Mythic (60), and Mythic+ (60).

• There are 8 "traditional" dungeons in Shadowlands. Of these dungeons, 4 are available for leveling players, with another 4 available at max level.

The item level of dropped gear depends on the difficulty of the dungeon and Shadowlands will not contain Warforging or Titanforging.

• Normal Dungeons drops Item Level 157 gear at Level 60.

• Heroic Dungeons drops Item Level 170 gear.

• Mythic Dungeons drops Item Level 183 gear.

To queue for Heroic Dungeons through the Dungeon Finder, you must be a certain item level (157), but you can walk in with a premade group at any point.  

Torghast is a different type of dungeon.  It can only be unlocked at level 60, following a short questline, and offers an ever changing dungeon for between 1 and 5 players.  The further you get through it, the greater the challenges.