What is rhetoric?

I first learned about the term rhetoric in english 103 last semester.  I remember talking about ethos, logos, and pathos.  Rhetoric means to me when you write or speak to persuade something or someone.  I think rhetoric is used in everyday speech, even in speaking.  I think that whenever you talk to someone, most of the time you are trying to persuade them to do something or think a certain way, whether the person believes it or not.  Rhetoric can be both positive and negative.