The concept of descriptive analytics, which is a branch of data analytics focused on summarizing historical data to identify patterns and trends. It explains that descriptive analytics is crucial for understanding past behaviors and events, which can help businesses make informed decisions. The article outlines various techniques used in descriptive analytics, such as data aggregation and data mining, and provides practical examples of how these techniques are applied in different industries. For instance, it might discuss how retail companies use sales data to understand customer purchasing patterns or how healthcare providers analyze patient data to improve treatment outcomes.