Throughout the Lands Between players will encounter many NPCs, some friendly, some not so friendly.
There are literally hundreds of NPCs in the game which can also be classed as enemy/creatures.
Some NPCs can appear more than once as you traverse the world so they will appear in different locations depending on your game progress.
Not all NPCs will be quest givers but there are few. See the quest guides section to see which NPCs will lead you on a sub quests.
Throughout the Land Between players will come across merchants where items can be purchased for runes (see map and select Merchants).
A full list of NPCs is available including their stars which players may find useful to identify their HP and resistances should they pose a problem.