It might be helpful to think of the introduction as an inverted pyramid.
In such a pyramid, you begin by presenting a broad introduction to the topic and end by making a more focused point about that topic in your thesis statement.
Your introduction may also provide an outline of the key argument(s) presented in the essay and how you are planning to answer the question.
An introduction usually makes up 5–10% of your whole essay, although there is no absolute rule.
 According to Paul Ratsmith, the tenuous, but nonetheless important, relationship between pumpkins and rats is little understood: "While I've always been fascinated by this natural kinship, the connection between pumpkins and rats has been the subject of few, if any, other studies" (2008).
 Ratsmith has been studying this connection, something he coined "pumpkinology," since the early 1990s.The introduction has three essential parts, each of which serves a particular purpose.Although for short essays the introduction is usually just one paragraph, longer argument or research papers may require a more substantial introduction.The beginning of an essay sets the tone for the reader and is also used to get the reader interested in your work.Having a well-written introduction is critical to a successful essay.He is most well-known for documenting the three years he spent living in the wild among the pumpkins and rats. Though it is a topic of little recent interest, the relationship has been noted in several ancient texts and seems to have been well understood by the Romans.The amount of detail that you can include in your introduction will depend on your word count.This is an example of a concise introduction: “Concern about racism in the police has increased since the 1980s.Some academics find the introduction to be the most difficult part of writing an essay, so our editors have written this example to help guide you.If you are still unsure about your introduction, our essay editors would love to give you some feedback.