This document discusses different ways to define and categorize audiences. It describes quantitative research which uses numbers and statistics to measure audience size. Qualitative research provides more in-depth opinions and reasons through methods like interviews. Socio-economic status categorizes people based on income, education and occupation. Psychographics examines personality, values and lifestyles. Geodemographics uses location data to group people. Other factors discussed include age, gender, and whether an audience is mainstream or niche. The document provides examples of how understanding these audience characteristics helps media producers target their content.