The document defines data as facts and measurements that can be numbers, words, or descriptions. It explains that there are two types of data: qualitative data, which is descriptive information, and quantitative data, which is numerical. Quantitative data can be discrete, taking certain values like whole numbers, or continuous, taking any value within a range. The document provides examples of qualitative data like descriptions of appearance and energy level, and quantitative data like weights, heights, and numbers of legs or brothers.