Rhetoric is the general term for a huge variety of devices and techniques - you could almost say tricks - used by speakers and writers to persuade an audience of a particular argument or point of view. The simplest example is probably the rhetorical question, which all of us use in everyday conversation without thinking about it. When you say to someone, 'Do you think I'm crazy?', you are not usually asking for information or even for an opinion: you are actually emphasising how uncrazy you are. Your 'question' does not require an answer because it is being asked rhetorically, for emphasis. Similarly a political speaker might say to a crowd, 'Are we going to be beaten into submission? Are we going to let them defeat us? Are we going to bow the knee to these dictators?' to stir the audience to anger and determination. Incidentally, starting these three questions with the same formula of words is another rhetorical device, called anaphora, which also puts rhythm into the speech: think of Churchill's 'We shall fight them...we shall fight them... we shall fight them...' Hyperbole, or deliberate exaggeration, is another, as is its opposite, deliberate understatement (can't remember the technical term - meiosis?). Even rearranging the usual order of words can have a strong rhetorical effect. For example, 'She is not a pleasant person' is not as strong as 'A pleasant person she is not'. There are loads more and I'm sure you'll find them easily on Google.