Q. What is a primary source?
Primary source materials are the original documents, created by participants or eye-witnesses. Diaries, letters, interviews are all primary sources. In the sciences, data, lab notebooks, and original test protocols could be considered primary documents. For example, in Computer Science source code or release notes are primary documents. In Biology, field observations or images are considered primary documents.
Q. What is a secondary source?
Secondary source materials describe, analyze or interpret primary source documents. Examples include textbooks, encyclopedia, commentaries and reviews.