The document discusses product mix, which refers to the complete set of products and services offered by a firm. It describes the key dimensions of a product mix as width, length, depth, and consistency. Width refers to the number of product lines, length to the total number of products, depth to variations within lines, and consistency to how closely related the lines are. The document provides examples from Kellogg's and Coca-Cola to illustrate these concepts. Maintaining an effective product mix can help a firm adjust to changes and reduce risks, while inconsistencies can hurt a brand.