An informative essay is any type of essay that has the goal of informing or educating an audience. By definition, it is not used to persuade or to give one's personal beliefs on a subject.
An informative essay contains three parts. The first part is the introduction. It is used to grab the attention of the reader and introduce the present topic. The second part is the bulk of the essay and contains all of the important facts being covered. The last part is the conclusion. This part should summarize the essay and encourage the reader to seek out more information about the topic.