Which of the following is the best explanation of how primary sources and secondary sources differ?

The distinction between primary and secondary sources is best captured by the understanding that secondary sources are derived from primary sources. Primary sources are original materials created at the time an event occurred or created by individuals directly involved in the event. Examples include letters, photographs, interviews, and original research reports. Secondary sources, on the other hand, interpret, analyze, or summarize information from primary sources. These can include textbooks, articles that review or critique research, and documentaries that provide context or analysis.

This understanding underscores that secondary sources do not present firsthand accounts or original data; instead, they build upon the information found in primary sources. Thus, recognizing that secondary sources rely on primary sources for their content is fundamental to grasping how researchers and scholars approach historical or analytical work.