Glossary            [A-D] - [E-J] - [K-P] - [Q-S] - [T-Z]

Table
1) A systematic arrangement of data presented in rows and/or columns with appropriate titles, captions, etc.; and
2) An arrangement of data items within a logical record in a summary tape file or other computerized medium, characterized by a common universe.

Tabulation
1) A table presenting statistics; and 2) the process of summarizing data.

TCP/IP*
A network communications protocol that forms the basis of most communications on the Internet.

Temperature 1
The degree of hotness or coldness as measured on some definite temperature scale

Tenure
Refers to the distinction between owner-occupied and renter-occupied housing units.
Related terms: Housing unit, Owner-occupied housing unit, Renter-occupied housing unit

Thematic map*
A map designed primarily to show a "theme," a single spatial distribution or pattern, using a specific map type.

TIF*
An industry standard raster graphic or image format.

TIGER*
A map data format based on zero, one, and two cells, used by the U.S. Census Bureau in street level mapping of the United States.

TIGER database
TIGER ® is an acronym for the Topologically Integrated Geographic Encoding and Referencing (System or database). It is a digital (computer-readable) geographic database that automates the mapping and related geographic activities required to support the U.S. Census Bureau's census and survey programs. The U.S. Census Bureau developed the TIGER System to automate the geographic support processes needed to meet the major geographic needs of the 1990 census: producing the cartographic products to support data collection and map presentations, providing the geographic structure for tabulation and dissemination of the collected statistical data, assigning residential and employer addresses to the correct geographic location and relating those locations to the geographic entities used for data tabulation, and so forth.

Topographic map*
A map type showing a limited set of features but including at the minimum information about elevations or landforms. Example: contour maps. Topographic maps are common for navigation and for use as reference maps.

Topology*
The numerical description of the relationships between geographic features, as encoded by adjacency, linkage, inclusion, or proximity. Thus a point can be inside a region, a line can connect to others, and a region can have neighbors.

Tract
See Census tract.

Tract number
Used to uniquely identify a census tract within a county.

Transparent overlay *
An analog method for map overlay, where maps are traced or photographed onto transparent paper or film and then overlain mechanically.

Tutorial
An on-line mini-course, part of the Arizona Electronic Atlas Help system, which demonstrates how to accomplish various important tasks.

Type of institution
Institutions are those facilities designed for group quarters living. Institutions may specialize in one specific type of service such as a prison, or may offer varied services such as Veteran's Administration hospitals.
Related terms: Group quarters (GQ), Institutionalized population

Type of school
Schools are designated as public or private institutions and are separated by levels of education offered, including: college, pre-primary, elementary or high school.
Related term: Educational attainment, School enrollment

Unemployed
All civilians 16 years old and over are classified as unemployed if they (1) were neither "at work" nor "with a job but not at work" during the reference week, and (2) were actively looking for work during the last 4 weeks, and (3) were available to accept a job. Also included as unemployed are civilians who did not work at all during the reference week, were waiting to be called back to a job from which they had been laid off, and were available for work except for temporary illness.
Related terms: Employed, Labor Force

Units*
The standardized measurement increments for values within an attribute.

Unix*
A computer operating system that has been made workable on virtually every possible computer and has become the operating system of choice for workstations and science and engineering applications.

Unmarried partner
A person who is not related to the householder, who shares living quarters with, and who has a close personal relationship with the householder.

Unmarried-partner household
Household in which the householder and his or her partner are not legally married or participating in a common law marriage.
Related terms: Household, Householder

Urban
All territory, population and housing units in urbanized areas and in places of more than 2,500 persons outside of urbanized areas. "Urban" classification cuts across other hierarchies and can be in metropolitan or non-metropolitan areas.
Related terms: Metropolitan, Rural

Urban Area
Collective term referring to all areas that are urban. For Census 2000, there are two types of urban areas: urban clusters and urbanized areas.

U.S. Census Bureau*
A part of the Department of Commerce that provides maps in support of the decennial (every 10 years) census of the United States, especially the census of population.

User interface*
The physical means of communication between a person and a software program or operating system. At its most basic, this is the exchange of typed statements in English or a program-like set of commands.

USGS (U. S. Geological Survey)*
A part of the Department of the Interior and a major provider of digital map data for the United States.

UTM (Universal Transverse Mercator)*
A standardized coordinate system based on the metric system and a division of the earth into sixty 6-degree-wide zones. Each zone is projected onto a transverse Mercator projection, and the coordinate origins are located systematically. Both civilian and military versions exist.

Vacancy status
Unoccupied housing units are considered vacant. Vacancy status is determined by the terms under which the unit may be occupied, e.g., for rent, for sale, or for seasonal use only.
Related terms: Housing unit, Occupied housing unit

Vacant housing unit
A housing unit is vacant if no one is living in it at the time of enumeration, unless its occupants are only temporarily absent. Units temporarily occupied at the time of enumeration entirely by people who have a usual residence elsewhere are also classified as vacant.
Related terms: Housing unit, Occupied housing unit

Value
Value is the respondent's estimate of how much the property (house and lot, mobile home and lot, or condominium unit) would sell for if it were for sale.

Vector*
A map data structure using the point or node and the connecting segment as the basic building block for representing geographic features.

Vegetation 2
Plant life; growing plants.

Veteran status
A "civilian veteran" is a person 18 years old or over who has served (even for a short time), but is not now serving, on active duty in the U.S. Army, Navy, Air Force, Marine Corps, or the Coast Guard, or who served in the U.S. Merchant Marine during World War II. People who served in the National Guard or military Reserves are classified as veterans only if they were ever called or ordered to active duty, not counting the 4-6 months for initial training or yearly summer camps. All other civilians 16 years old and over are classified as nonveterans.

Voting District (VTD)
Any of a variety of areas, such as election districts, precincts, legislative districts, or wards, established by states and local governments for voting purposes.
Related terms: Redistricting

Watershed 3
The land area that drains into a stream; the watershed for a major river may encompass a number of smaller watersheds that ultimately combine at a common point.

Watershed Area 3
A topographic area within a line drawn connecting the highest points uphill of a drinking water intake into which overland flow drains.

Waterways

Well 2
A shaft or hole into the Earth to tap an underground supply of water.

Wetland 2
A low-lying area that is water-logged and forms when a lake or pond fills with sediment.

Wilderness areas

Worker
This term appears in connection with several subjects: journey-to-work items, class of worker, work status in the past 12 months, weeks worked in the past 12 months, and number of workers in family in the past 12 months. Its meaning varies and, therefore, should be determined in each case by referring to the definition of the subject in which it appears.
Related terms: Employed

Year structure built
The data on year structure built were obtained from both occupied and vacant housing units. Year structure built refers to when the building was first constructed, not when it was remodeled, added to, or converted. The data relate to the number of units built during the specified periods that were still in existence at the time of enumeration.
Related term: Housing unit

ZIP Code
A ZIP (Zone Improvement Plan) Code is a five-, seven-, nine-, or eleven-digit code assigned by the U.S. Postal Service to a section of a street, a collection of streets, an establishment, structure, or group of post office boxes, for the delivery of mail.
The Census Bureau uses only 5-digit ZIP codes for the addresses and address ranges in most Census 2000 operations.

ZIP Code Tabulation Area (ZCTA)
A ZIP Code Tabulation Area is a geographic area that approximates the delivery area for a five-digit or a three-digit ZIP Code. ZCTAs do not precisely depict the area within which mail deliveries associated with that ZIP Code occur.
A five-digit ZCTA ending in "XX" (e.g., "006XX") represents the land area within a three-digit ZCTA that is not associated with any mail delivery route.

Zone (of a coordinate system)*
The region over which the coordinates relate with respect to a single origin. Usually, some part of the earth or a state.

Zoom-In
Zooms in to show greater detail for a portion of the map.

Zoom-Out
Zooms out to show less detail for the map.

* Clarke, Keith C. Getting Started with Geographic Information Systems. 4th edition Upper Saddle River, N.J., 2003.
1 Oklahoma Climatological Survey Glossary - http://k12.ocs.ou.edu/teachers/glossary/
2 USGS Glossary - http://interactive2.usgs.gov/glossary -Page no longer available.
3 EPA Terms of Environment - http://www.epa.gov/OCEPAterms
All other definitions from American Factfinder - http://factfinder.census.gov/servlet/BasicFactsServlet - click on Glossary

For other Glossaries, see http://www.gis.com/whatisgis/glossaries.html