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Open UI

Open UI Jargon

There is a lot of jargon in the world of web standards. We strive within the Open UI project to be a safe and inclusive space for beginners. We know this means using accessible language. Unfortunately, the web platform has built up a lot of acronyms and jargon that can be overwhelming to parse.


  • Specification: a document that describes how a component should work.
  • Anatomy: The parts that make up the control/component (e.g. <popup>)
  • States: The various states of the control/component that this can be in (e.g. <popup state="open">)
  • Behaviors: The implications of state changes on various parts of the anatomy (eg: aria, rendering, state changes)
  • Graduated Specification: a specification that has been moved to a standards body, like WHATWG, or the W3C.
  • Component: The dictionary defines a component as, “a part or element of a larger whole” and this is true for components in a design system’s component library. Components normally have a meaning, although this meaning may not be presented to the user (such as a utility component). The meaning is defined by the component’s model, defined parts and slots, and states.
  • Control: A control is a type of component that allows some form of user interaction. The control has controller code that manages the transition of the component’s states and the model based on end user interaction with the defined parts.
  • Composite Component: It is often necessary to produce a component that contains other components. For example, the <file> control is a component that normally contains an <input> component and a <button> component. These types of components are commonly referred to as composite components.

The Web Platform Contribution Guide also has a jargon glossary which might help demistify some concepts: