Primary and secondary data
Primary data is collected first-hand for the exact question at hand, such as a firm's own survey. Secondary data was collected earlier by someone else for another purpose and is simply reused.
See it move
A bakery chain deciding whether to open a new branch commissions its own 200-shopper street survey on bread demand — primary data, collected first-hand for this exact question. It also reuses the national statistics office's income and population figures for the district — secondary data, originally compiled for general reporting and repurposed here.
Check yourself
A university careers office wants to know the starting salaries of last year's graduates from one master's programme. It emails all 220 graduates directly and receives 150 responses. It also downloads the national statistics agency's most recent average graduate salary figures for general context. Which data source is primary, and which is secondary?