Definition: wikipedia. Commonly used as a way to transfer actual raster data across the internet (as opposed to Web Mapping Services (WMSs) which send raster graphics). Strictly speaking, WCS can be used send any georeferenced set of points. WCS will not uniquely identify any point as a "feature." This requires a different service type, the OGC Web Feature Service (WFS).
Specification Maintainer: The Open Geospatial Consortium (OGC)
Reference Implementation: GeoServer