Primary research is a form of research where the researching individual collecting new found information by conducting interviews, surveys, focus group, trip and any evidence the researcher collects such as photographs. Where secondary research uses found knowledge from the internet, books/newspapers other analysis that the researcher did not conduct. Primary research is a good way to find out information for your target demographic for your product/service you want to produce, whereas if you use secondary research you get an overall estimation of your target demographic, as it's someone elses research.
I was tasked to create a survey, based on the filming industry on Cinemas. Surveys are useful in collecting data and getting other people opinions without going door to door or conducting 200 interviews but it depends of the type of situation. Many other primary research types conclude of: interviews, focus groups and experiments.