The term talk means communicating with a non-player character (NPC) by right-clicking on them. Player characters communicate with each other through chat.
Additional notes:
- You should see a speech bubble icon (
) with a small triangle (silver 
or gold 
) when you move your pointer over the creature.
- If your character is too far away to talk, the small triangle will be silver.
- out of range
- If your character is close enough to talk, the small triangle will be gold.
- in range to talk
Note: You can speak to NPCs in druid forms as of Patch 2.0.3.