Definition and Classification of Statistics?

Statistics is the study of data and how to analyze it. The goal is to understand patterns, trends, and relationships between data points. This is done using different tools and methods.

Statistics can be divided into two broad categories: descriptive statistics and inferential statistics. Descriptive statistics are used to describe a set of data, such as mean, median, mode and standard deviation. Inferential statistics try to draw conclusions based on the descriptive statistics. For example, if we want to know what percentage of the population lives in cities with more than 10 million people, we can use a simple table of population by city size. If we want to draw any conclusions about this relationship (i.e., that people living in large cities tend to have higher income), then we would need an inferential statistical model that uses this table as input and outputs an estimate for our question "What percentage of people live in cities with more than 10 million people?"