Primary
Primary Research is research that you conduct yourself and examples can include Questionnaires, telephone interviews and focus groups.
Secondary
Secondary Research is when you collate existing research that you have found and summarise it, the main difference is that secondary research has already been analyzed and interpreted by the primary authors.
Qualitative
Qualitative research is research that is based on written results that are harder to categorize than numbers.
Quantitative
Quantitative Research is research into facts and statistics and anything that can be statistically defined with numbers.