TOPIC / ISSUE
A topic is what the essay or research
paper is about. It provides a focus for the writing. Of course, the
major topic can be broken down into its components or smaller pieces
(e.g., the major topic of nuclear waste disposal may be broken down
into medical, economic, and environmental concerns). But the important
thing to remember is that you should stick with just one major topic
per essay or research paper in order to have a coherent piece of
writing.
An issue is a concept upon which you can take a
stand. While "nuclear waste" is a topic, "safe and economic disposal
of nuclear waste" is an issue, or a "point of discussion, debate, or
dispute" (American Heritage Dictionary).