Online analytical processing is a methodological approach and set of computational techniques focused on the rapid execution of complex analytical queries against aggregated, multi-dimensional data structures. It investigates patterns, trends, and anomalies within large datasets to support strategic decision-making. Key characteristics include the use of multi-dimensional data models (e.g., data cubes) to facilitate interactive exploration along various dimensions, enabling efficient, user-driven data aggregation and analysis crucial for business intelligence and decision support systems.