Web Feature Service (WFS) is a key complementary technology to GML. It is to GML as HTTP Servers are to HTML. A key objective of GML was to support geospatial transactions and WFS provides the means to realize that objective.
A WFS is intended to serve geographic content in the form of GML features. It is not intended as a mapping engine. The latter is the role of the Web Map Service (WMS).
A WFS can be read-only or support both reading and transactional operations. Some people designate the transactional WFS by using the label WFS-T. All Galdos WFS are transactional.
A WFS responds to XML messages that encode requests for geographic information or which describe geospatial transactions on features (e.g. insert, delete, update a feature). A WFS can thus respond to messages like:
- Find all abandoned water wells within Watkin County which are older than 1984
- Find the owners of properties whose area exceeds 20 hectares in France.
- Modify the road’s centerline geometry to the following …
- Delete the Firth Bridge specified by id = “pog21”
- Insert a new observation feature – the sampling of the water at the dam at 3:00 pm 2007-1-16
