In 2004, White Wolf Game studio relaunched their successful range of horror style RPGs under the World Of Darkness (WoD) setting. Confusingly, they called the new setting... World Of Darkness, but it is significantly different from the previous product line. The Goth-Punk and apocolyptic themes were gone, and the over-arching metaplot with a final ending were dropped. The new World Of Darkness games were more open-ended and mysterious, holding to a dark mystery theme without being utterly nihilistic.
Another major change was a shift in the core rules. The StoryTelling system was retained with tweaks, and a single core rules set was introduced, usefully called... World Of Darkness. The different genre games (Vampires, Werewolves and so on) were now available as supplements to these core rules, with each supplement bringing in rules specific to that type.
Players distinguish between the two settings by calling the original WoD setting Old World Of Darkness (oWoD) and there is a separate Family in the database for that. The new setting is known by fans as New World Of Darkness (nWoD), but this is not official. This Family is for the nWoD games.
In December of 2015, Onyx Path Publishing and White Wolf Publishing "...announce[d] that Chronicles of Darkness is now the overall brand name for the series of game lines previously called the New World of Darkness."
Key RPGG links for nWoD material:
The World of Darkness RPG
The World of Darkness core book
The World of Darkness setting
If you are looking for the oWod (Old World of Darkness - pre 2004) families, they are at:
World of Darkness RPGs (oWoD)
Mind's Eye Theatre (oWoD)
For more information see:
World of Darkness on VideoGameGeek.