The three are:
-Ethos
-Pathos
-Logos
Ethos is basically the appeal to ethics, and it is a means of convincing someone of the character or credibility of the persuader.
Pathos is used to appeal to emotion, and is a way of convincing an audience of an argument by creating an emotional response.
Finally, Logos is an appeal to logic, and is used to persuade an audience by reason.
