Collection of Data — Economics STD 11 Commerce — Question

It is rightly said that the difference between primary data and secondary data is of degree. Data collected by X will be primary for X and secondary for everyone else. The one who collects any data, data are primary in his hands and as soon as any other person wants to use it, it becomes secondary. For example, Population Census is conducted by the government of India every 10 years, it is primary for the government but when a book writer takes data of demographic condition of India from the reports of these census, it is secondary for him. Therefore, it is rightly said first hand data. Only in first hand, it is primary. When it goes to second hand, it becomes secondary.