Many definitions cite the ISO 191xx Geographic information standards written by ISO/TC211.

Reference model (ISO 19101-1 Fundamentals, ISO 19101-2 Imagery)

Feature: an abstraction of a real world phenomenon. (ISO 19101-1)

  • Feature type: class of features having common characteristics.
  • Feature attribute: characteristic of a feature.
  • Feature operation: operation that every instance of a feature type can perform.


Geographic: about phenomena on or near the Earth's surface. (ISO 19101-1)

(graphic presentation of geospatial data.)

Geographic Information System (GIS): a computer program dealing with geospatial data (ISO 19101-1); such as to create, store, analyze and display.

Geoprocessing: computer systems for Earth imaging, surveying, digital cartography, spatial database operations, and location based services (such as navigation).

Coverage: a feature that is a function for any direct position within its spatial, temporal or spatio-temporal domain. (ISO 19101-1) Including raster image, digital elevation matrix, and polygon overlay.

Raster: usually rectangular pattern of parallel scanning lines forming or corresponding to the display on a cathode ray tube. (ISO 19101-1) A raster is a type of grid.

Imagery: representation of phenomena as images produced by electronic or optical techniques. (ISO 19101-2)

Measurement: set of operations that determine the value of a quantity. (VIM)

Observation: e.g. temperature, ppm, chemical type.

Spatial Schema (ISO 19107)

Feature Collection (Record): a finite, named collection of related features.


Vector geometry: representation of geometry through the use of constructive geometric primitives.

Computational geometry: manipulation of and calculations with geometric representations for the implementation of geometric operations.

Geometric primitive: geometric object representing a single, connected, homogeneous element of space.

  1. Point: 0-dimensional geometric primitive, representing a position.
  2. Curve: 1-dimensional geometric primitive, representing the continuous image of a line.
  3. Surface: 2-dimensional geometric primitive, representing the continuous image of a region of a plane.
  4. Solid: 3-dimensional geometric primitive, representing the continuous image of a region of Euclidean 3 space.

Cycle: spatial object without a boundary.

  • Ring: a simple curve which is a cycle.
  • Shell: a simple surface which is a cycle.

Geometric complex: set of disjoint geometric primitives, where the boundary of each geometric primitive can be represented as the union of other geometric primitives of smaller dimension within the same set.

  1. Composite curve: sequence of curves such that each curve (except the first) starts at the end point of the previous curve in the sequence.
  2. Composite surface: connected set of surfaces adjoining one another along shared boundary curves.
  3. Composite solid: connected set of solids adjoining one another along shared boundary surfaces.


Topology: Invariant property of geometries under continuous transformations.

Topological object: spatial object representing spatial characteristics that are invariant under continuous transformations.

Computational topology: operations on topological objects usually performed in computational geometry.

Topological primitive: topological object representing a single non-decomposable element.

  1. Node: 0-dimensional topological primitive.
  2. Edge: 1-dimensional topological primitive.
  3. Face: 2-dimensional topological primitive.
  4. Topological solid: 3-dimensional topological primitive.

Topological complex: collection of topological objects that is closed under the boundary operations.

  • Graph: set of nodes, some of which are joined by edges.

Geometric realization: geometric complex whose geometric primitives are in a 1-to-1 correspondence to the topological primitives of a topological complex, such that the boundary relations in the two complexes agree.


Geographical poles: the two points on the Earth where it meets its axis of rotation. The Earth's axis of rotation moves relative to the crust, referred to as polar motion. Averaged locations of geographical poles are used for cartographic and other terrestrial purposes.

Circle of latitude (parallel 纬线): intersection of the Earth's surface and a cone surface symmetric about the Earth's axis of rotation.

Equator: the great circle of the Earth intersected by the plane orthogonal to the Earth's axis of rotation and passing the center of the Earth.

Meridian (经线, 子午线): intersection of the Earth's surface and a half-plane bounded by the Earth's axis of rotation, defining a line of longitude.

Prime meridian (本初子午线): the meridian where longitude is defined to be 0°. Various conventions have been used in different regions and throughout history.

Spatial Referencing by Coordinates (ISO 19111)

Direct position: position described by a single set of coordinates within a coordinate reference system. (ISO 19107)

Coordinate: one of a sequence of N-numbers designating the position of a point in N-dimensional space.

Coordinate System: set of mathematical rules for specifying how coordinates are to be assigned to points.

Coordinate Reference System: coordinate system that is related to the real world by a datum.


OGC Glossary

ESRI GIS Dictionary

GIS Glossary: short definition with illustration.

🏷 Category=Geographic Information System