Topology in GIS is the relationship between objects that connect. The concept occurs most often in the context of topological errors associated with vector objects. The main errors are:

- stall (overshoot) and,
- undershoot.

Correcting topological errors is critical in the context of running network analyses (e.g. Gate Analysis, Sewer Analysis) and Water Supply Modelling.

Correct spatial data is free of topological errors. These errors result in incorrect algorithms, e.g. the shortest path finding. A tool that facilitates editing data without topological errors is Snapping.

Comparison

The topology of the network is equally critical in, for example, car navigation data. It is easy to imagine that a deficient road to an intersection, will result in a diversion because the algorithm considers that there is no correct connection.