Pathos (Greek for 'suffering' or 'experience') is often associated with emotional appeal. It is an appeal to an audience's emotions. But a better equivalent might be 'appeal to the audience's sympathies and imagination. An appeal to pathos causes an audience not just to respond emotionally but to identify with the writer's point of view--to feel what the writer feels. In this sense, pathos evokes a meaning implicit in the verb 'to suffer'--to feel pain imaginatively.
Ethos (Credibility), or ethical appeal, occurs when you are convinced by the author or speaker because you find him/her to be a credible source of information. The term comes from the Greek word which means character. We tend to believe people whom we respect. One of the central problems of argumentation is to project an impression to the reader that you are someone worth listening to, in other words making yourself a figure of authority on the subject of the paper, as well as someone who is likable and worthy of respect.
Greek for "word/reason" Persuading through the use use of logic. It is used to describe facts and evidence that support the speaker's topic.