The Web Feature Service (WFS) is an interface specified by the Open Geospatial Consortium (OGC) that allows for the exchange of geographic data across the Web.
The OpenGIS Web Map Service Interface Standard (WMS) provides a simple HTTP interface for requesting geo-registered map images from one or more distributed geospatial databases.
A web service is a generic term for an interoperable machine-to-machine software function that is hosted at a network addressable location. A web service has an interface that hides the implementation details so that it can be used independently of the hardware or software platform on which it is implemented and independently of the programming language in which it is written.
NASA's EOSDIS Worldview visualization application provides the capability to interactively browse more than 1,000 global, full-resolution satellite imagery layers and then download the underlying data. Many of the available imagery layers are updated generally within three hours of observation, essentially showing Earth as it looks "right now." This supports time-critical application areas such as wildfire management, air quality measurements, and flood monitoring.