GIS Dictionary

[data structures] Features of one type that are generally placed together in a single layer.

[map design] A map designed to convey information about a single topic or theme, such as population density or geology.

[ESRI software] In ArcView 3.x, a set of related geographic features such as streets, parcels, or rivers, along with their attributes. All features in a theme share the same coordinate … Read more

[ESRI software] In ArcView 3.x, a document object linked to the set of features in a theme. It serves as an interface to the underlying database, allowing manipulation of the … Read more

[ESRI software] In ArcView 3.x, an operation in which features in one theme are selected based on their spatial relationships with features in another theme. Theme-on-theme selection is used to … Read more

[surveying] A surveying instrument for measuring vertical and horizontal angles, consisting of an alidade, a telescope, and graduated circles mounted vertically and horizontally.

[Euclidean geometry] Polygons generated from a set of sample points. Each Thiessen polygon defines an area of influence around its sample point, so that any location inside the polygon is … Read more

[database structures] The third level of guidelines for designing table and data structures in a relational database. The third-normal-form guideline incorporates the guidelines of first and second normal form; in … Read more

[software] A process flow through an application. An application can have many threads.

[software] A software configuration in which three software applications (commonly a client program, application server, and database server) work together to accomplish a task.

In business analysis, an operation that creates rings that contain a given population around a store or stores on a map.

1 [graphics computing] A miniaturized version of a graphics file. A thumbnail can be used as a visual index for larger data or images. 2 [ESRI software] In ArcGIS, a … Read more