At 05:14 PM 9/5/01 +0200, Martyn Horner wrote:
An RDF Glossary
- The world (and the world of information that it encloses) contains a vast number of `entities' - things we talk about and think about. Many have names and words in human languages, some have no name but can be referred to in passing.
- Anything which exists or has existed. Note that RFC2396 uses this term in a more restricted sense, to mean some data represents some aspect of a Web Resource.
- [MH] Actually [RFC2396] doesn't attempt to define `entity'.
- The universe in which RDF operates is seen as a potentially huge collection of `resources'.
- Resources are the identifiable items in the world, the contact points between you and the world of data. They are `entities' as we need to refer to them, fixed for a short time while we talk about them.
- A typical resource would be a unit of data on the Web such as a page or a significant segment of a page. Equally another person, an organization or anything else that you would wish to point at out there in this universe can be referred to as a `resource'. The significant characteristic is the identifiable nature of resources, that they have for whatever period of time an identity which makes them distinguishable.
- [RDFT&C] May refer to an RDF resource or a Web Resource. Some resources may be both. In discussion of RDF, this term is often used to mean RDF Resource.
- A resource may be an entire Web page; such as the HTML document "http://www.w3.org/Overview.html" for example. A resource may be a part of a Web page; e.g. a specific HTML or XML element within the document source. A resource may also be a whole collection of pages; e.g. an entire Web site. A resource may also be an object that is not directly accessible via the Web; e.g. a printed book. Resources are always named by URIs plus optional anchor ids (see [URI]). Anything can have a URI; the extensibility of URIs allows the introduction of identifiers for any entity imaginable.
- An abstract object that represents either a physical object such as a person or a book or a conceptual object such as a color or the class of things that have colors. Web pages are usually considered to be physical objects, but the distinction between physical and conceptual or abstract objects is not important to RDF. A resource can also be a component of a larger object; for example, a resource can represent a specific person's left hand or a specific paragraph out of a document. As used in this specification, the term resource refers to the whole of an object if the URI does not contain a fragment (anchor) id or to the specific subunit named by the fragment or anchor id.
- [Jena] Some entity. It could be a web resource such as web page, or it could be a concrete physical thing such as a tree or a car. It could be an abstract idea such as chess or football. Resources are named by URIs.
- [N3] That identified by a Universal Resource Identifier (without a "#"). If the URI starts "http:", then the resource is some form of generic document.
- Resources which have their identity by nature of their accessibility on the World Wide Web are sometimes distinguished as `Web Resources'. To make this identification, we may have to chose one aspect of this entity's contact with the Web - for an organization: a particular Web page, for a person: an email account, etc.
- Anything that is identified by a URI
- [Dan Connolly (email)] Nope; that rules out real numbers...
- [Accessibility] anything that has identity on the Web. A Web resource is identified by a URI.
- [WebChar] A resource, identified by a URI, that is a member of the Web Core (The collection of resources residing on the Internet that can be accessed using any implemented version of HTTP as part of the protocol stack (or its equivalent), either directly or via an intermediary. Notes: By the term "or its equivalent" we consider any version of HTTP that is currently implemented as well as any new standards which may replace HTTP (HTTP-NG, for example). Also, we include any protocol stack including HTTP at any level, for example HTTP running over SSL.).
- [RFC2616] A network data object or service that can be identified by a URI, as defined in section 3.2. Resources may be available in multiple representations (e.g. multiple languages, data formats, size, and resolutions) or vary in other ways.
- [RFC2396 (in context of defining URI)] A resource can be anything that has identity. Familiar examples include an electronic document, an image, a service (e.g., "today's weather report for Los Angeles"), and a collection of other resources. Not all resources are network "retrievable"; e.g., human beings, corporations, and bound books in a library can also be considered resources. The resource is the conceptual mapping to an entity or set of entities, not necessarily the entity which corresponds to that mapping at any particular instance in time. Thus, a resource can remain constant even when its content---the entities to which it currently corresponds---changes over time, provided that the conceptual mapping is not changed in the process