Data type: URL.

A body of structured information describing some topic(s) of interest.

Instances of the class [Observation](http://schema.org/Observation) are used to specify observations about an entity (which may or may not be an instance of a [StatisticalPopulation](http://schema.org/StatisticalPopulation)), at a particular time. The principal properties of an [Observation](http://schema.org/Observation) are [observedNode](http://schema.org/observedNode), [measuredProperty](http://schema.org/measuredProperty), [measuredValue](http://schema.org/measuredValue) (or [median](http://schema.org/median), etc.) and [observationDate](http://schema.org/observationDate) ([measuredProperty](http://schema.org/measuredProperty) properties can, but need not always, be W3C RDF Data Cube "measure properties", as in the [lifeExpectancy example](https://www.w3.org/TR/vocab-data-cube/#dsd-example)).See also [StatisticalPopulation](http://schema.org/StatisticalPopulation), and the [data and datasets](https://schema.org/docs/data-and-datasets.html) overview for more details.

WebContent is a type representing all [WebPage](http://schema.org/WebPage), [WebSite](http://schema.org/WebSite) and [WebPageElement](http://schema.org/WebPageElement) content. It is sometimes the case that detailed distinctions between Web pages, sites and their parts is not always important or obvious. The [WebContent](http://schema.org/WebContent) type makes it easier to describe Web-addressable content without requiring such distinctions to always be stated. (The intent is that the existing types [WebPage](http://schema.org/WebPage), [WebSite](http://schema.org/WebSite) and [WebPageElement](http://schema.org/WebPageElement) will eventually be declared as subtypes of [WebContent](http://schema.org/WebContent).)