What is H3 and how does it work in geospatial analysis

H3 is a hexagon-based, hierarchical spatial indexing system designed to transform the Earth's surface into a consistent grid for analyzing location data, with each hexagonal cell having a unique ID. Created by Uber to support large-scale marketplace analysis, H3 is particularly effective for aggregating large point datasets, density analysis, and comparing patterns across regions, offering a more consistent and scalable approach than traditional latitude/longitude coordinates or administrative boundaries. The hexagonal grid reduces quantization errors and ensures smoother neighbor geometry, making it ideal for understanding supply and demand, pricing, or movement patterns within a city. H3 supports 16 resolution levels, allowing users to choose cell sizes that match their analysis needs, from broad regional patterns to detailed neighborhood hotspots. Tools like Felt facilitate the visualization of H3 data, enabling interactive mapping and data exploration without technical complexity, making it suitable for modern analytics workflows that require converting spatial questions into tabular forms for group analysis and comparison.