Working in the realm of standards (on the web or elsewhere) you eventually realise that there are a lot of terms, not all of which mean what they may initially seem to, or what they are always used for.  This post is an attempt to simply explain some of these common concepts.

Specifications

Or ‘specs’. These are formal documents describing a technology, protocol, or other pattern that may be standardised. A standard cannot exist without a specification, but a specification is not automatically a standard of any kind. Specifications are key in allowing interoperability.

Examples: OAuth, OpenID, EAUT, PortableContacts, HTML4.01, XMPP

Interoperability

Is when two or more implementations of a specification can “talk to” each other, without prior knowledge of the other implementation.

Examples: Psi and Google Talk, Firefox and Opera, USB keys

Implementation

A product, service, or similar that conforms (or claims to conform) to a particular specification.

Standards Body

Or standards organisation. A self-proclaimed shepherd of standards. These bodies hold different amounts of influence with different implementors, based on their membership. Some of these bodies provide resources to those working on specifications they have claimed as “their standards”.

Standards bodies get all of their authority from their membership. These organisations may claim specifications are standards that no one outside them considers to be standards.

Examples: W3C, IETF, OASIS, ISO, ECMA

Open Specification

A specification that has been released to the public under a liberal license.

Standards Community / Open Community

A community that has rallied around a specification or set of specifications. The community seeks to promote and maintain the specifications, and often refers to them as “standards”.

Example: PortableContacts Initiative

An “open” community operates in the open, with transparency into all aspects and discussions. Usually operate on mailing lists and IRC channels.

Example: microformats community

Standard

Not everyone agrees what comprises a “standard”, but many people agree that the term is overused and abused. I will here state my own interpretation of “standard”:

1. A standard has a specification
2. The specification has multiple, independant implementations
3. One or more of these implementations is interoperable
4. One or more of these implementations is libre software
5. One or more of these implementations is “popular”
6. There is an implementation for each relevant platform (OSs, browsers, etc)

Notice that the blessing of a standards body or community is not necessary.

Examples: RTF, HTML4.01, XMPP, H.262

Open Standard

A standard whose specification is an open specification. In addition, the specification should be clear of all patent encumbrances (may be necessary to be considered an open specification).

Examples: OpenID, OAuth, XHTML1.1, microformats

See also: On Language Extensions (in Haskell and Elsewhere)