On the Edit tab, in the Manage Edits group, the Topology arrow toggles topological editing on and off. When you enable Map Topology you can edit topological edges and nodes for all visible features using tools in the Modify Features pane. Enabling a Geodatabase Topology rule limits topological editing to only the layers that participate in the selected topology.
Editing features as topological edges and nodes maintains feature contiguity by enforcing edges to remain coincident as you edit features. Map topology 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 the 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.
For a list of editing tools that can edit map and geodatabase topology, see Modify Features tool reference.
Map topology options
On the Map Topologies Options dialog box, the cluster tolerance is the distance within which edges and vertices are determined to be coincident. 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.
To learn how to create geodatabase topology, see Create a topology.
Geodatabase topologies model spatial relationships by representing features as topological primitives. When you validate a topology, an alternative rules-based topological view of your feature geometry is generated as group layers. 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.