This might also be an appropriate place to introduce the reader to key terms and provide definitions, if required.
Simply create two overlapping circles, one for each of the topics that you are comparing.
The introduction usually starts by providing some background information to your particular topic, so the reader understands the key problem being addressed and why it is an issue worth writing about.
However, it is important that this is brief and that you only include information that is directly relevant to the topic.
A good compare-and-contrast essay goes beyond a simple listing of similarities and differences to make a meaningful statement about a larger topic.
When you look at the lists you’ve made, what strikes you as significant?