
Arc
A line connected to two end points.

Area
A spatial feature that is represented by a series of lines and has the geometric properties of size and perimeter. Also called polygon, face, or zone.

Area definition
A topological relationship used in ESRI's coverage model, which stipulates that an area is defined by a series of connected arcs.

Connectivity
A topological relationship used in ESRI's coverage model, which stipulates that arcs connect to each other at nodes.

Contiguity
A topological vector data format used in ESRI products.

Coverage
A topological vector data format used in ESRI products.

Delaunay triangulation
A iterative process of connecting points with their two nearest neighbors to form triangles as equiangular as possible in a triangulated irregular network (TIN).

Event
An attribute that can be associated and displayed with a route.

Georelational data model
A GIS data model that stores spatial data and attribute data in two separate but related file systems.

Graph theory
A subfield of mathematics that uses diagrams or graphs to study the arrangements of objects and the relationships between objects.

Line
A spatial feature that is represented by a series of points and has the geometric properities of location and length. Also called arc, edge, link, or chain.

Node
The beginning or end point of a line.

Point
A spatial feature that is represented by a pair of coordinates and has only the geometric property of location. Also called node or vertex.

Route
A linear feature that allows linear measures to be used on a projected coordinate system.

Section
A part of a route that refers directly to the underlying arcs and positions along arcs.

Shapefile
A nontopological vector data format used in ESRI products.

Topology
A subfield of mathematics that studies properties of geometric objects, which remain invariant under certain transformations such as bending or stretching.

Triangulated irregualar network (TIN)
A vector data model that approximates the terrain with a set of nonoverlapping triangles.

Vector data model
A data model that uses points and their x, ycoordinates to construct spatial features.

