In connection with business or marketing research process, which involves, among others, data collection, secondary data refers to data or information that has already been collected and compiled by others, rather than data gathered firsthand by the user (the so-called primary data).

Secondary data are published and available to the public, whether in a format of books, magazines, journals, or online (websites).

Reliance on secondary data may be less costly, though it should be gathered anyway in order to avoid incurring unnecessary costs.