Coverage

A coverage is a vector-based digital map data structure used in the ARC/INFO Geographic Information System (GIS) to store, organize, and manage spatial data. It represents geographic features using arcs (lines), nodes (endpoints and intersections), polygons (areas), and label points that identify features within polygons. These components work together to accurately model real-world objects such as roads, rivers, land parcels, and administrative boundaries.

One of the defining features of a coverage is its built-in topology, which records spatial relationships between features. Topology defines how lines connect, which arcs form polygons, and how adjacent features share common boundaries. This structure improves data integrity, minimizes duplication and spatial errors, and enables advanced GIS operations, including network analysis, overlay processing, adjacency analysis, and connectivity modeling.

Each coverage generally represents a single thematic layer, such as transportation, hydrography, land use, soils, or elevation. It also includes attribute tables that store descriptive information for each spatial feature, allowing users to link geographic geometry with real-world data for efficient analysis and mapping.