Research can be defined as systematically investigating a topic to discover new facts or information. There are two main types of research: primary research involves collecting original data, while secondary research uses existing information from outside sources. Qualitative research aims to understand opinions and motivations through methods like interviews, while quantitative research uses numerical data from surveys to measure trends and generalize results. Examples of both types are described, including a biography of Che Guevara and a case study on treating obesity. Key sources of audience data for TV (BARB) and radio (RAJAR) in the UK are also summarized.