Primary data is data collected directly from firsthand sources through surveys, observation or experimentation. It provides accurate information specific to the research problem but can be costly and time-consuming to collect. Secondary data already exists and is cheaper and easier to obtain but the researcher has less control over what is collected. Qualitative research uses unstructured methods like focus groups and in-depth interviews to provide insights while quantitative research quantifies data using structured methods like telephone, online, and mail surveys. Both have advantages and disadvantages depending on the research needs.