The second expansion of WoW is called "Wrath of The Lich King" and it was released simultaneously worldwide on 13 November 2008. There were a lot of changes, here is a little summary:

• The reachable level of characters was raised to 80;
• A new continent was added, it's called Northrend from level that is about the size of half of any of these two continents under the edition of World of Warcraft); it is located far north of Azeroth, that contains 11 regions which cover characters from level 68 to level 80:

1. Borean Tundra, from level 68 to level 72
2. Howling Fjord, from level 68 to level 72
3. Dragonblight, from level 71 to level 74
4. Grizzly Hills, from level 73 to level 75
5. Crystalsong Forest, from level 74 to level 76
6. Zul'Drak, from level 74 to level 77
7. Sholazar Basin, from level 75 to level 78
8. Storm Peaks, from level 76 to level 80
9. Hrothgar's Landing, from level 77 to level 80 (that was added with an after-patch, 3.2.0)
10. Icecrown, from level 77 to level 80 (where the Lich King lives)
11. Wintergrasp, from level 77 to level 80 (this region is fully dedicated for PvP).

• New raid instance and version to be addressed in Normal or Heroic.
• Adding a new Inscription profession which allows the creation of scrolls and Glyph (3 major and 3 minor that will enhance and improve certain skills).
• Introduction of a class, which was Hero Class, now called the Death Knight.
• Introduction of a new PvP event called Wintergrasp Siege that takes place in the homonymous area.