N-GIS Glossary,

This glossary is a sub-set of one developed by the Urban and Regional Information
Systems Association (URISA)

Network Analysis
Specialized queries that reference connected linear and node features.

1. Typical analytical transactions within Transportation Networks: Modifying direction and/or impedance along links and through intersections. Identifying the optimal path as measured between two or more points according to a selected terms of measurement. Highlighting all components (nodes and links) of the optimal path, referred to as "routing".
2. Typical analytical transactions within Utility Networks: Modifying direction and ON/OFF position settings of links relative to nodes. Isolating all network nodes and links both physically and logically connected to a selected test point. Highlighting all logically connected network features, referred to a "Network Tracing". Attribute records linked to highlighted features can be subsequently isolated to perform design analysis.
3. Two types of utility networks: Pressure Networks. Typical transactions include resetting valves to redirect service operations or reset switches to reconfigure circuits. Typically applies to water, gas, steam, electric and telephone systems. Gravity Networks. Typical transactions include isolating all nodes and links upstream or downstream from a test point. Can include isolating a portion of the network by changing position settings of links relative to their upstream or downstream nodes to OFF. Typically applies to sewer, storm, telephone, and sometimes electric utilities.
4. Typical analysis performed using records linked to highlighted features in a route or trace include load loss, traffic demand and capacity, pressure loss, maximum flow, gradient, asset management and other engineering analysis.

Network Routing
In transportation networks, this refers to highlighting all node and link features along the optimal path between a starting point and one or more destinations, either in terms of least distance, travel time, or other prescribed performance criteria. See Network Analysis.

Network Tracing
In utility networks, this refers to highlighting all node and link features within a gravity of pressure network that are both physically and logically connected to a test point within the network according to a specified set of rules. See Utility Network, Network Analysis, Network Link, and Network Node.

Non-Graphic Database (also Non-Spatial)
This phrase refers to a set of tabular data records, each record containing multiple data fields. In the context of spatial databases, one of these fields is the Unique ID Number of a corresponding map feature.