The Web Coverage Service is an OGC specification for providing coverage data (vector and/or raster plus attribute information). This is an extention of the Web Map Server specification – which just proivdes a raster image.
A OGC OWS specification - this time for coverages.
Compare and contrast with GCE.
Several specifications exist:
Extends the Web Map Server (WMS) interface to allow access to geospatial "coverages" that represent values or properties of geographic locations, rather than WMS generated maps (pictures).
This is a OWS style service with a GETCAPABILITIES document describing the service, rather than something normal like XMLRPC or SOAP