In an essay, you explain your ideas on a subject by taking the reader through your thought process. Not only do you say what you think, but you show your reader why you think it. They see your reasons, your evidence, the things you’ve noticed, and the judgements you’ve made in order to arrive at your opinion. The best essays are very clearly and logically laid out - like an arrow being shot from a bow — your opinion is the arrow and the line of argument is like its flight path.