In
research, secondary data is
data collected and possibly processed by people other than the researcher in question. Common sources of secondary data for social science include censuses, large surveys, and organizational records. In historical research
secondary sources are summaries, collections, and interpretations of primary sources.
See more at Wikipedia.org...
information that is obtained from previously published materials, such as books, magazines, newspapers, government census publications and company reports and files. See
Primary Data.