Descriptive expository essays describe a topic by providing specific details about its characteristics. For example, if you are writing about an experience at the beach, you might focus on what it felt like to walk barefoot in the sand, what it smelled like as the wind wafted over the water, and what it sounded like as the waves gently slapped against the beach. Each of these characteristics would likely be addressed in its own paragraph or section of paragraphs.
Sequential expository essays describe a sequence of events or items, usually in a chronological order. For example, if you are asked to write a description of your observation of a traffic accident, you would likely begin by describing what you observed just prior to the accident before describing your observations of the initial impact of the vehicles followed by the events that occurred in the immediate aftermath. You would likely address each these sequential observations in a separate paragraph or section.
Comparative expository essays provide a comparative description of two or more items, highlighting their similarities and differences. For example, if you are writing a comparison of your experience eating a banana and an apple, you would describe your experience of each fruit according to specific criteria including, for instance, their texture, taste and nutritional value. You would organize your comparison around these criteria, addressing both the banana and the apple in each paragraph or section.
Cause-and-effect expository essays express the relationship between two or more items or experiences. For example, if you are writing an essay in which you describe several reasons why so many people watch the Super Bowl every year, you might address causal factors including advertising for the event and its history as an American cultural pastime. Each of these causal factors could be described in its own paragraph or section of paragraphs.