The expository essay has the characteristics that the writer does not offer an opinion but just outlines the opinions of others. It is often used as the tool in journalism.
The difference in an expository essay is seen in the way the ideas are put together. The subject is outlined in detail but without anything other than facts. Critical evaluation is not used much but a good expository essay does also provide explanation. Which makes it not simply a report. You will need to be exact in your language usage and use language tools such as analogies. Analysis of evidence is the normal technique used in the expository essay, in both research and structure.