What is the differences between primary secondary and tertiary information sources?

Primary information sources provide direct, firsthand evidence or original data, such as research articles, interviews, and official documents. Secondary sources interpret, analyze, or summarize primary data, including review articles, biographies, and critiques. Tertiary sources compile and organize information from primary and secondary sources, like encyclopedias, textbooks, and databases, serving as reference tools for quick information retrieval. Each type serves a distinct purpose in research and information gathering.