"Primary" refers to the first or main level of something. In education, primary schools are where children typically receive their first formal instruction. In research, primary data is original data collected firsthand for a specific purpose, such as surveys or experiments. "Secondary" refers to something that is derived from or comes after the primary level. In education, secondary schools follow primary schools and cater to older students. In research, secondary data is information that has already been collected and published, such as articles or reports, which researchers use to analyze trends or support their findings.