Research confuses me: what is qualitative research & what is the difference between grounded theory and phenomenology?

What is qualitative research? Are there different types of qualitative research? Is qualitative research important in medicine? Is it not enough for me to understand quantitative research and its methodology? It is unsurprising that medical students might feel overwhelmed studying many different research study designs. Some might even do as some of us initially did: we “skim-read” the chapters on qualitative analyses. We reasoned that so much medical teaching and medical literature relies on numbers (pvalues, confidence intervals, odds ratios, relative risks, etc), the “hard data”. By comparison, qualitative research has more words and fewer numbers. The outcomes can sometimes appear “obvious”, and we wondered if so much effort was needed or justified. However, the benefits of qualitative research in medicine are widely recognised and accepted. This extends especially to the Cochrane Database of Systematic Reviews, where systematic reviews of qualitative studies are conducted.