Directory of instances of a class or classes of features containing some information regarding position

Geocoding is the process of linking words, terms and codes found in a text string to their applicable geospatial features, with known positions (i.e., usually a point with x, y coordinates but more generally any geometry), e.g. converting a street address to a geographic location. The Geocoder Service Interface allows for a request providing an address or set of addresses and returns them along with the corresponding geometry (usually a point relative to a requested spatial reference system.) The request is "sent" to a Geocoder Service, which processes the request and returns the resulting geographic feature representing position.

Translation of one form of location into another

Digital data that represent the geographical location and characteristics of natural or man-made features, phenomena and boundaries of the Earth. Geodata represent abstractions of real-world entities, such as roads, buildings, vehicles, lakes, forests and countries. Geodata refers to such data in any format, including raster, vector, point, text, video, database records, etc.

related to the science of earth measurement (geodesy).

Datum describing the relationship of a two- or three-dimensional coordinate system to the Earth.

A reference system that uses latitude and longitude to define the locations of points on the surface of a sphere or spheroid. A geographic coordinate system definition includes a datum, prime meridian, and angular unit. geographic coordinate system Illustration.

Representation of real world phenomenon associated with a location relative to the Earth

Information concerning phenomena implicitly or explicitly associated with a location relative to the Earth

Service that transforms, manages, or presents geographic information to users

Information system dealing with information concerning phenomena associated with location relative to the Earth.

[GIS dictionary] GIS is a computer-based tool that analyzes, stores, manipulates and visualizes geographic information on a map. GIS links geographic locations on Earth with attribute information enabling users to visualize patterns, understand relationships and trends.

Geography is the study of the Earth and its lands, features, inhabitants, and phenomena.

Source: http://wiki.gis.com/wiki/index.php/Geography