Aggregate data refers to high-level data that is acquired by combining individual-level data from multiple sources and compiling it into summary reports. It is used in statistics, data warehouses, economics, and other fields. Aggregate data is different from individual data, which refers to disaggregated individual results and is used to conduct analyses for estimation of subgroup differences.

Data aggregation is the process of gathering and expressing raw data in a summary form for statistical analysis. When data is aggregated, atomic data rows are replaced with summary data, such as averages, percentages, or proportions. Data aggregation is often used to provide statistical analysis for groups of people and to create useful summary data for business analysis. It can enable analysts to access and examine large amounts of data in a reasonable time frame.

Examples of aggregate data include overall price level or overall inflation rate in macroeconomics, and data of an entire sector of an economy composed of many firms or of all households in a city or region in microeconomics. In public education, aggregate data is used to provide useful information about the performance of public schools and public-school students to those who are monitoring schools or working to improve them.

In summary, aggregate data is high-level data that is compiled from individual-level data from multiple sources and is used for statistical analysis and business intelligence. Data aggregation is the process of summarizing raw data into useful summary data.