Edges

Edges represent a part of a line or boundary of a polygon, for example, a section of a road or county boundary.

Every edge has a node at the start and a node at the end. If the line is made up of several edges, the nodes at the start and end of each edge are shared.

If two polygons (such as two buildings) share part of the boundary, the edges are shared. Sharing edges identifies the co-linearity of two features and ensures that no slivers are introduced between the edges.

Note: If the boundaries are close to touching, these will be snapped to share the edge.

In planar topology, edges never overlap. If any data is made up of overlapping or crossing lines, the edges are split and nodes are formed at the intersections.

In network topology, edges can overlap depending on the snapping type.

Edges exist in the system datastore as sys:edge.

An edge has the following references:

Reference	Description
sys:edge_to_node	sys:edge and sys:node are related by the reference if the node is at the start or end of the edge.
sys:area_to_edge (polygons)	Area and sys:edge are related by the reference if the polygon has a boundary represented by an edge.
sys:line_to_edge	A line feature and sys:edge are related by the reference when an edge represents the feature in the topology.