Here's why:
* Secondary sources are documents that analyze, interpret, or summarize primary sources. Encyclopedias are compilations of information gathered from various primary sources, such as research papers, historical documents, or interviews.
* Primary sources are original materials that provide firsthand accounts or evidence, like diaries, letters, photographs, or scientific data.
Therefore, while an encyclopedia can provide valuable information, it's not the original source of the information. It's a secondary source that presents information compiled from primary sources.