GIS Glossary
Frequently used terms in GIS, with definitions. Jump to a letter below.
A
- ArcGIS Enterprise
- An on-premise Esri platform offering AGOL-like capabilities on the organization's own servers.
- ArcGIS Online (AGOL)
- Esri's cloud-based platform for sharing maps and producing web apps.
- ArcGIS Pro
- Esri's modern 64-bit desktop GIS application.
- Attribute Data
- Tabular numeric/textual information describing a spatial feature (e.g., population, name, elevation).
B
- Basemap
- A reference background map (satellite, streets, topography) over which other layers are drawn.
C
- Cartography
- The science and art of map design and production.
- Coordinate System
- A reference framework that numerically defines the location of spatial data.
D
- Datum
- The reference that anchors a coordinate system to the Earth's ellipsoid model (e.g., WGS84, ED50).
- DEM (Digital Elevation Model)
- A raster dataset representing terrain elevations as cell values.
- Digitizing
- The process of producing vector data from an analog map or scanned image.
- DTM / DSM
- | Elevation models of bare earth (DTM) versus all surface objects including buildings/trees (DSM).
F
- Feature Class
- A data structure holding spatial features that share the same geometry type and attributes.
G
- Geodatabase |
- An Esri database structure that stores spatial and non-spatial data together.
- Geographic Coordinate System (GCS)
- A latitude–longitude based system describing the entire globe (e.g., WGS 84).
- Geoprocessing
- Operations that analyze, transform, or manage spatial data.
- Georeferencing
- Assigning real-world coordinates to an image or scan without spatial reference.
- GIS (Geographic Information System)
- An information system designed to capture, store, analyze, and visualize spatial data referenced to the.
L
- Layer
- A data set representing a specific theme that can be stacked on a map with other layers.
- Layout
- The design surface for producing printable / shareable map outputs.
- Legend
- The map element that explains what each symbol represents.|
- Line / Polyline
- A geometry connecting two or more points (e.g., road, river).
M
- Map
- A 2D data visualization view inside ArcGIS Pro.
- Metadata
- Descriptive information about a dataset's source, date, accuracy, and ownership.
- Model Builder
- The visual interface in ArcGIS Pro for chaining geoprocessing tools into workflows.
P
- Point
- The smallest geometry, represented by a single coordinate pair (e.g., tree, well).
- Polygon
- A geometry that defines an enclosed area (e.g., parcel, district boundary).
- Project (.aprx)
- The ArcGIS Pro file that bundles maps, scenes, layouts, and tasks together.
- Projected Coordinate System (PCS)
- A system that flattens the globe onto a plane with metric units (e.g., UTM, Web Mercator).
- Projection
- The mathematical method of transferring the 3D Earth onto a 2D plane.
R
- Raster Data
- Cell- (pixel-) based spatial data stored in a grid structure (satellite imagery, DEM, etc.).
S
- Scale
- The ratio between map distance and real-world distance (e.g., 1:25,000).
- Scene
- A 3D data visualization view inside ArcGIS Pro.
- Shapefile
- A classic Esri vector format consisting of multiple files (.shp, .dbf, .shx).
- Spatial Data
- Data that references a location on Earth and carries coordinate information.
- Symbology |
- The visual style — color, symbol, size — used to represent spatial data on a map.
T
U
- UTM (Universal Transverse Mercator)
- A projection that divides the world into 6° zones, producing metric coordinates per zone.
V
- Vector Data
- Spatial data represented by point, line, and polygon geometries.