Qualitative data are those measurements taken in words.
Some socio demographics are measured qualitatively. Some examples are educational level, medical history, favorite color, occupation, gender, and race. All of them are measured in words.
In health and medical sciences, examples of qualitative data include level of agreement (Strongly disagree/Disagree/Agree/Strongly agree), occurrence of adverse events (Yes/No), and open comments regarding the efficacy of a treatment.