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.
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