The vector data model represents geographic features as discrete geometries — points, lines and polygons — defined by coordinate pairs and linked to attribute tables. A well, a road centreline and a land parcel are natural vector features. Vector data is the backbone of cadastre, utility networks, transport databases and administrative boundaries, because it stores crisp edges, exact positions and rich attributes with great storage efficiency.
Geometry plus attributes
A vector feature couples a geometry with a database row. The geometry holds coordinates — one pair for a point, an ordered chain for a line, a closed ring (possibly with holes) for a polygon. The attribute row holds everything else: an owner name, a pipe diameter, a road class, a population count.
This coupling is what makes vector GIS feel like a spatial database. You can select features by attribute (all pipes larger than 300 mm), by location (all parcels within a flood zone), or both at once — and every selection is simultaneously a map and a table.
Common vector formats
The venerable shapefile is still everywhere despite its age and limitations. Modern work increasingly uses GeoPackage, file and enterprise geodatabases, PostGIS tables and GeoJSON for the web. Formats differ in size limits, attribute richness, topology support and multi-user editing — choosing well saves pain later.
Interchange between formats is a routine production task, but a deceptively tricky one: coordinate systems, field types, character encodings and geometry validity all present conversion traps that quietly corrupt data when handled carelessly.
When vector is the right choice
Vector excels wherever features have defined boundaries and identities: parcels, assets, networks, administrative units, addresses. It supports exact measurement, network connectivity and one-to-one links between map objects and business records.
It is the wrong tool for continuously varying phenomena — elevation, temperature, reflectance — where the raster model is natural. Mature GIS work mixes both, converting between them deliberately rather than by accident.