Answer:
A cause/effect essay is an essay which explains the reason why a particular phenomenon happens, and lists its effects. In this kind of an essay, we examine the reasons and results of a particular situation. The essay structure typically includes an introduction, body paragraphs and conclusion. A topic for a cause and effect essay is, for instance, air pollution. In this essay, we would examine the reason why air pollution is present, and discuss its (negative) effect on our environment.
A compare/contrast essay is an essay which evaluates the similarities and differences between two subjects. The subjects are usually from the same category, but have certain differences. For instance, we might write an essay where we compare and contrast two characters from a literary work, or two novels written in the same period.