On the Edit tab, in the Manage Edits group, the Topology arrow toggles topological editing on and off. Choosing Map Topology enables edge and node editing for all layers in the map. Choosing a geodatabase topology enables edge and node editing only for the layers participating in the selected topology rule.
Map and geodatabase topologies can help you enforce connectivity, contiguity, and other spatial relationships among features in a map. Each has its own unique uses and workflow. They both display an alternative rules-based topological view of your feature geometry and enable a specific set of editing tools for ensuring the quality of your data.
Topologies model spatial relationships by representing features as an underlying graph of topological primitives comprising nodes, faces, and edges. These primitives, together with their relationships to one another and to the features whose boundaries they represent, are defined by representing the feature geometries in a planar graph of topological elements.
This topic explains the basic differences between map topology and geodatabase topology. For detailed steps to edit a topology using a specific tool, browse the table of contents or search for a particular keyword or workflow. For a list of editing tools that can edit map and geodatabase topology, see Modify Features tool reference.
Map topology maintains coincident edges as you edit features. It requires no setup. When it is enabled, it appears as a highlighted graph of edges and nodes that correlate directly to the visible features you are editing. Editing tools that can switch between editing finished features and map topology contain Features and Edges tabs that allow you to toggle between these editing modes.
The workflow is similar to moving or editing features, except that features that share an edge or a node are also automatically edited and remain contiguous when you finish the edit. If you attempt to finish edits that break the topology graph, the message Edit operation failed appears, and your changes are canceled.
The cluster tolerance is the distance within which edges and vertices are determined to be coincident. On the Map Topologies Options dialog box, you can choose to have ArcGIS Pro automatically calculate a minimum possible value, or you can specify a custom tolerance. For most use cases, the automatic setting is the best practice.
Geodatabase topology is a rules-based methodology that involves defining spatial relationships in the source geodatabase, validating them in a map, and fixing the errors. Spatial relationships that violate a rule are symbolized as errors on separate topology layers in your map. The status of a topology, including errors and exceptions, is saved to the source geodatabase.
For example, in a geodatabase, you can define a topology for features contained in a Roads dataset and specify that all road and highway intersections must include a coincident point feature. After creating or editing these features, you can validate your work, identify the features that do not conform to this rule, and edit the features to make corrections.
When you validate a topology, you can fix errors using predefined fixes or common editing tools. To learn how to validate a geodatabase topology and fix errors, see Validate and fix geodatabase topology.