Glossary

1. The software and documentation components that together, conform to accessibility requirements. This is the most common use of the term in this document and is the usage in the checkpoints.
2. Any software that retrieves and renders Web content for users. This may include Web browsers, media players, plug-ins, and other programs — including assistive technologies— that help in retrieving and rendering Web content.

Style property values applied in the absence of any author or user styles.

1. the user agent user interface, i.e., the controls (e.g., menus, buttons, prompts, and other components for input and output) and mechanisms (e.g., selection and focus) provided by the user agent ("out of the box") that are not created by content.
   AND
2. the "content user interface," i.e., the enabled elements  that are part of content, such as form controls, links, and applets.

Style property values that come from user interface settings, user style sheets, or other user interactions.