The WFS and WMS Services OGC Web Services for accessing Geographic Data

The WFS and WMS Services

OGC Web Services for accessing Geographic Data

The
Open Geospatial Consortium


has defined several Open Web Services for accessing (usually geographic) data. There are two basic service sets – the Web Feature Services (WFS) and the Web Map Services (WMS). The WFS is concerned with direct access to your data – reading, writing, and updating
your
features. The WMS is concerned with transforming your data into a map (image).

What is a Feature? A feature is an Object that is an abstraction of a real world phenomenon. This object has a set of properties associated with each having a name, a type, and a value. An example of a feature might be Road with a Name, Location (line geometry), Width, Speed Limit, and Jurisdiction. Typically these features are stored in a spatial database, shapefile, or other format.

OGC Open Web Services The OGC Web Services provide access to the features – either directly or as images (maps) – in a standardized way independent of the company who created the server or the actual format the data is stored in.

What to use a the WFS services for

A WFS allows uniform direct access to the features stored on a server. Use a WFS when they want to perform actions such as:

query a dataset and retrieve the features
find the feature definition (feature’s property names and types)
add features to dataset
delete feature from a dataset
update feature in a dataset
lock features to prevent modification

A WMS allows for uniform rendering access to features stored on a server. Use a WMS when you want to perform actions such
as:

Producing Maps
Very simple Querying of data