The Web's Uniform Interface is based on a large and growing set of specifications. These specifications establish the shared concepts that providers and consumers of Web services can rely on. Web Concepts is providing an overview of these concepts and of the specifications defining them. One example for how this works is the Hypertext Markup Language (HTML), which defines the media type text/html and a set of link relation types such as alternate and section. Web Concepts provides a structured, quick, and interlinked overview of these and many more concepts that together establish the Web surface.