1. 主要数据：
当一个机构或研究人员第一次从头到尾收集数据时，这种数据称为原始数据，它是原始数据，即最先完全更新的数据，称为原始数据。它是从头开始收集大量资金用于收集原始数据。同时，也需要人力，即也需要人。
2. 二手资料：
二手数据是机构或研究人员已经收集的数据，新研究人员会生成有关使用这些已收集数据的新信息。例如，如果您已经拥有印度的人口数据，那么您可以轻松找出您所在城市的识字人口百分比和文盲百分比，但是您已经从印度的人口数据中收集了该数据 因此，此数据将称为辅助数据。
主要和次要数据之间的差异：
| S.NO | Primary Data | Secondary Data |
|---|---|---|
| 1. | Primary data is the first data collected by a researcher for the first time. | Whereas secondary data is a data that is already collected by someone earlier. |
| 2. | Primary data is called real-time data. | While this is not real-time data, it is related to the past. |
| 3. | The process is very much involved in collecting primary data. | While collecting secondary data it does not involve much process but rather quickly and easily. |
| 4. | Primary data is cost effective. | While it is economical. |
| 5. | The primary data takes long time for collection. | While secondary data takes shorter time than primary data for collection. |
| 6. | Primary data is available in crud form. | While it is available in processed or refined form. |
| 7. | Primary data is more accurate than secondary data. | While it is less accurate than primary data. |
| 8. | Primary data is more reliable than secondary data. | While secondary data is less reliable than primary data. |
| 9. | There is also difficulty in collecting data. | While there is no difficulty in collecting data. |