What is the difference between qualitative and quantitative research?

Qualitative research methods use large representative samples; quantitative research methods use smaller and sometimes non$-$representative samples.

Qualitative research methods collect numerical data; quantitative research methods collect non$-$numerical data.

Qualitative research is cross$-$sectional; quantitative research is longitudinal.

Qualitative research methods are unstructured or semi$-$structured and use loosely ordered processes; quantitative research methods are structured and use formal processes.

Qualitative research results in primary data; quantitative research results in secondary data.