This document discusses different methods for classifying audiences, including demographics like gender, age, and location, as well as socioeconomic class and lifestyle segmentation models. It describes several popular audience classification systems such as using socioeconomic class labels (A, B, C1, C2, D, E), the 4C's Marketing Model that places audiences into groups based on cultural characteristics, and The LifeMatrix approach which defines ten audience categories based on values, attitudes, and demographics.