Basically, research can be either quantitative or qualitative.
Quantitative methods have been widely used because of the fact that things that can be measured or counted gain scientific credibility over the unmeasurable. But the extent of biological abnormality, severity, consequences and the impact of illness cannot be satisfactorily captured and answered by the quantitative research alone. In such situations qualitative methods take a holistic perspective preserving the complexities of human behavior by addressing the “why” and “how” questions.Lakshman, M., Sinha, L., Biswas, M., Charles, M., & Arora, N. K. (2000). Quantitative vs qualitative research methods. The indian journal of pediatrics, 67(5), 369-377.
As a new researcher, you may want to read more about this matter. Besides doing only one type of research design, you can also utilize both by using mixed-method study design.
Mixed methods research is the type of research in which a researcher or team of researchers combines elements of qualitative and quantitative research approaches (e. g., use of qualitative and quantitative viewpoints, data collection, analysis, inference techniques) for the broad purposes of breadth and depth of understanding and corroboration.Johnson, R. B., Onwuegbuzie, A. J., & Turner, L. A. (2007). Toward a definition of mixed methods research. Journal of mixed methods research, 1(2), 112-133.