Classification charts and timelines are tools to organize information chronologically or categorically. Classification charts illustrate the structure of a field by differentiating ideas and objects. They explain how items are alike or different in various ways through headings. Timelines present a chronological sequence of related events along a line from left to right or top to bottom. They establish a time span, determine a style, enter significant dates, and provide concise facts and information for each date to help the reader quickly understand relationships limited by time.