Emotes are animations that can be triggered by the player's input in the chat box, sending a message on the Emotes channel. Emotes can't be used while in combat or mounted. If you're targeting anything, the emote's message will mention its name. For example, if you type /wave while targeting a player named Target, it'll say "Player waves at Target".
List of Emotes
To see a list of all available emotes, type /emotes.
Using every emote unlocks the Emotional achievement.