The OpenGIS Web Feature Service Interface Standard (WFS) is an interface allowing requests for geographical features across the web being highly interoperable.
It uses the XML
-based Geographic Markup Language (GML) for data exchange. This means that instead of returning an
image, as WMS services (described below) do, the service returns a GML file containing both the geometry and the attribute.
An OGC Web Map Service (WMS) produces maps of spatially referenced data dynamically from geographic information.
This International Standard defines a "map" to be a portrayal of geographic information as a digital image file
suitable for display on a computer screen. A map is not the data itself. WMS-produced maps are generally rendered in
a pictorial format such as PNG, GIF or JPEG, or occasionally as vector-based graphical elements in Scalable Vector
Graphics (SVG) or Web Computer Graphics Metafile (WebCGM) formats.
Simply defined, metadata is "data about data." Used in the context of
digital spatial data, metadata is the background information which describes
the content, quality, condition, and other appropriate characteristics
of the data. Paper maps contain metadata, primarily as part of the map
legend. In this form, metadata is readily apparent and easily transferred
between map producers and map users. When map data are in a digital
form, metadata is equally as important, but its development and maintenance
often require a more conscious effort on the part of data producers
and the chain of subsequent users who may modify the data to suit their
Metadata can help preserve the usefulness of a data set within an organization.
If metadata is created according to the federal
and contributed to an NSDI
, it becomes possible for other users to search for
and find this information and its related data effectively.
... still unsure?
in plain language
or the unofficial
FAQ on FGDC Metadata
This page leads to summaries of most of the known metadata tools used
for documenting geospatial data and serving geospatial metadata. It
includes tools for entering and editing metadata and utilities for preprocessing,
extracting, postprocessing, and validating metadata. Most of these tools
were designed to help complete Content Standards for Digital Geospatial
Metadata (CSDGM) metadata, but several have been tuned to produce specific
local metadata profiles.
Soup to nuts on metadata issues, resources, tools, and getting started
for the metadata novice to the metadata maestro.