Here's why:
* Secondary sources analyze or interpret primary sources. A bibliography is simply a list of sources, it doesn't offer analysis or interpretation.
* A bibliography helps you find primary and secondary sources. It's a tool for research, not a source of information itself.
Think of it this way:
* Primary source: The original document, like a historical letter or scientific study.
* Secondary source: A book or article that analyzes or interprets a primary source, like a biography or a journal article summarizing a study.
* Bibliography: A list of primary and secondary sources that could be helpful for researching a topic.
Let me know if you have any other questions!