Differentiate between topic and talking headings.

Topic headings are short constructions, consisting of one or two words. They merely identify the topic of discussion as in "Cost" or "Space Requirements."
Talking headings also identify the subject matter to be covered, but they go a step further: They also indicate what is said about the subject. In other words, talking headings summarize the material they cover, as in "Increase in Cost of Operation" or "Less Space Required."