Research is a careful hunting for facts or truth about a subject. It is a inquiry and investigation into the precedents, the evidence and the logic. Different methods of research are appropriate for different topics or different levels of study. Students, for example, would consider an encyclopedia as an appropriate source for research, but professional historians would want to look at original documents. Scientific research generally involves labwork, where "social science" research tends to work with documents, artifacts, or "in the field" interviews.
Good researchers should always make sure they do not just parrot the source material's point of view, but that they try to find balanced points of view.