GIS Data Models Vocabulary

Vocabulary flashcards covering GIS Data Models, including vector/raster concepts, table attributes, conversions, and ArcGIS data structures.

The GIS Process Diagram

A continuous operational workflow cycle consisting of defining protocols, collecting and editing spatial data, performing analysis, reporting results, deciding and acting, and interacting with the physical world.

Entity

A real-world object that possesses a spatial location, geometry and extent, thematic attributes, and temporal attributes.

Data Model

The logical means of representing and manipulating spatially-referenced information for use in an information system.

Data Structure

The physical file type by which a map feature or attribute is digitally encoded (e.g., shapefile, coverage, ESRI GRID, or ERDAS image file).

Spatial Attribute

An attribute that defines the physical location of a feature using addresses or geographic coordinates.

Non-Spatial Attribute

Descriptive thematic facts, qualities, or properties associated with a geographic feature, such as name, type, or color.

Temporal Attribute

An attribute recording time information related to an entity, such as when it existed or when its data was collected.

Record (GIS Table)

A row in an attribute table that represents an individual spatial feature.

Field (GIS Table)

A column in an attribute table that stores a specific attribute or characteristic across all features.

Cell (Attribute Table)

An individual cell in an attribute table that holds the specific value of an attribute for a single feature record.

Vector Data Model

A spatial data model where features are represented as discrete points, lines, or polygons stored using $x, y$ coordinates.

Raster Data Model

A spatial data model that represents space as a regular grid of square cells (tessellation), where each cell holds a single value.

Point

A standalone, 0-dimensional vector feature defined by a single set of $x, y$ coordinates (e.g., a school or fire station).

Line

A 1-dimensional vector feature defined by connecting starting, ending, and intermediate coordinate points (e.g., a river or road).

Node

The starting or ending point of a line feature in a vector data model.

Vertex

An intermediate coordinate point along a vector line feature where the line changes direction.

Polygon

An enclosed 2-dimensional vector feature representing an area (e.g., a lake).

Vector Feature Geometry Diagram

A geometric layout illustrating how points, lines, nodes, vertices, and polygons are represented in coordinate space.

Cell Resolution

The size of a raster cell defined in ground linear distance, representing the side length of the square cell.

Vector vs. Raster Comparison Table

A summary chart comparing spatial accuracy, efficiency, attribute storage capacity, comprehendability, and topological capabilities between vector and raster models.

Raster-to-Vector Conversion

The process of converting raster grid cell data into discrete vector geometry (vectorization).

Vector-to-Raster Conversion

The process of converting vector features into a regular grid of raster cells at a specified pixel size (rasterization).

Data Frame

An ArcGIS container that groups multiple layers registered to the same geographic location.

Feature Class

A collection of spatial data that shares the same geometry data type.

Feature Dataset

A collection of feature classes that share the same spatial reference.

Workspace

A container that holds both spatial data (feature classes, rasters) and non-spatial data (tables).

ArcGIS Basic Terms Structure

The structural relationships in ArcGIS linking Workspaces, Feature Datasets, Feature Classes, and non-spatial tables.