Extensible Hypertext Markup Language (XHTML)

 XHTML is a reformation of HTML as an XML vocabulary. This is a good idea, as it eliminates a lot of the problems that arose from the existence of proprietary or badly coded HTML , because it must now follow the strict rules of XML . XHTML is an XML application that specifies how XML can be used to describe a web page. XHTML documents look very similar to HTML documents, except they follow the rules of XML (which include things like all tags must have a matching closing tag, attributes must be quoted, tags must be nested properly and there must be a root tag for the overall document). XHTML is a subset of XML , but XML is not a subset of XHTML.The ultimate goal of using XHTML is to separate display/presentation tags from the document data/structure and to use the elements as they were meant to be used. The key change to make, is separating presentation from content.

Extensible Markup Language (XML)

 XML A language specification from the W3C that allows users to develop their own markup languages (often called vocabularies), and format their documents using stylesheets to be presented on a browser if desired. It is a syntax/format, establishing rules for XML -compliant languages with a very strict set of rules that must be adhered to, allowing lots of control over document format.

Extensible Style Language (XSL)

 XSL is a W3C specification that contains 3 parts. Extensible Stylesheet Language Transformations (XSLT) for changing the formatting and structure of markup according to a set of rules, Extensible Stylesheet Language Formatting Objects (XSL-FO) for applying a strong set of rules to a document to ensure reliable formatting when printed, and XPath to select the elements required by an XSLT.

Universal Access

 The idea that all things (on the Internet) should be accessible by the largest audience possible, regardless of disability, location, device, or speed of connection to the Internet. The ability of everyone, regardless of age, nationality, disability, or any other factor, to access and take advantage of a website.

Universal Design

 Designing for the largest audience possible regardless of disability or ability to speak the native language. This is a process rather than an end in itself.

Universal Selector

 In CSS, a universial selector is depicted by an asterisk. It is a kind of a wild card. It acts like a type element, except it matches any and every element it can. Therefore, * {color: red;} would turn every element in an entire document red.

Usability

 Usability is the art and science of designing systems or products that are effective, efficient, engaging, error tolerant and easy to learn. Usability and accessibility are often confused. Some believe that a usable site is accessible and vice versa. The two are not exclusive, but it is important to understand the difference. Usability means that a Web site is intuitive and easy to use. Accessibility means a Web site is as barrier-free as possible. Accessibility and usability are closely related, as they both improve satisfaction, effectiveness, and efficiency of the generic user population. But while accessibility is aimed at making the website open to a much wider user population, usability is aimed at making the target population of the website happier, more efficient, more effective.

Usability Lab

 A usability lab is a facility specifically for user testing. It can be portable or fixed and may vary widely in how it is equipped. It is usually a quiet room with computer equipment and a place for an observer to sit, along with a special observation area (possibly behind a one-way mirror), and equipment for videotaping. Computers in a usability lab are also often set up with logging software to capture user keystrokes and mouse movements and with scan converters, used to videotape computer screens. For more information see: Labs.

Usability Testing

 Usability testing is the process of carrying out experiments to find out specific information about a design. It is part three of the "Usability Evaluation Toolbox". In usability testing, representative users work on typical tasks using the website (or a prototype) and the evaluators use the results to see how the user interface supports the users in doing their tasks. For more information see: Testing.

User Agent

  Software to access Web content, including desktop graphical browsers, text browsers, voice browsers, mobile phones, multimedia players, plug-ins, and some software assistive technologies used in conjunction with browsers such as screen readers, screen magnifiers, and voice recognition software. Browsers are a subset of user agents. All browsers are user agents, but not all user agents are browsers.
 

User Centered Design (UCD)

 The design process that places the user at the center of the design rather than the object to be designed. It is a philosophy and process rather than an end in itself.

User Interface Markup Language (UIML)

Unlike many markup languages, UMIL is not used to describe documents, rather it is used to describe elements on the page such as buttons, menu lists, and other page elements generally used in graphical user interfaces. It is used to define their placement on the page, and the actions to be taken when certain events such as mouse clicks, or keystrokes occur.

User Style Sheet

   A user can write a style sheet and make it override the browser's default style sheets as well as any styles a designer creates. A user style sheet will override browser/designer styles for that user only. A user style sheet is stored on the user's hard drive. Each browser has it's own instructions for configuring one. User style sheets can help people with special needs, such as low vision. If a user chooses to do so with CSS2, he or she can set rules to be more important than any style rules created by the web page designer with the "!important" operator. If a user's style sheet contains "!important", it takes precedence over any applicable rule in an designer's style sheet.

User Style Sheet

   A user can write a style sheet and make it override the browser's default style sheets as well as any styles a designer creates. A user style sheet will override browser/designer styles for that user only. A user style sheet is stored on the user's hard drive. Each browser has it's own instructions for configuring one. User style sheets can help people with special needs, such as low vision. If a user chooses to do so with CSS2, he or she can set rules to be more important than any style rules created by the web page designer with the "!important" operator. If a user's style sheet contains "!important", it takes precedence over any applicable rule in an designer's style sheet.

Valid HTML

 A Web page or HTML document is considered valid when it complies with World Wide Web Consortium recommendations.

Validation

 Validation is the process of verifying that markup, cascading style sheets, etc. comply with World Wide Web Consortium recommendations. You can use the W3C HTML Validator to verify that your pages meet the standards. It is important to use use structural markup according to published formal grammars. For more information see validation.

Value

  In CSS , a value is a length, quality, type or URL assigned to a style property for an element. CSS properties each have specific ranges of value or token types which may be declared for them.

Variable

  In programming, variables represent data. Like all programming languages, PHP allows you to store bits of data in variables, and then to access that data by writing the variable's name. A variable is probably most simply explained as an area of memory set aside to store information, and it is assigned a particular identifier by the programmer. In PHP, all variable names must start with the dollar sign character "$". There is no limit on the length of a variable. Variable names in PHP are case-sensitive.

Veranda

 Veranda is a humanist sans serif font designed by master typographer Matthew Carter. Microsoft commissioned Carter to create two faces specifically for web use, and the results were Veranda and Georgia (a serif face), probably they are good general purpose faces available for low resolution displays of the web. Verdana's, regular spacing makes it more readable on screen. Cartier has said that "Wider spacing wasn't enough, it also had to be more regular, this was thing that gave it an advantage in readability. Verdana really isn't wide, the sensation of width comes from the spacing".

Vertical- align

 In CSS, vertical- align is a property that affects the vertical positioning inside a line box of the boxes generated by an inline-level element. It applies only to inline elements, although that includes replaced elements such as images and form inputs. It is not inherited. Element content is typically vertically centered on a rendered line (with extra line-height amounts distributed equally on the top and bottom.) This property allows inline content boxes to be vertically aligned with respect to several different criteria on a rendered line.

Visual Disability

 The condition of a person who experiences partial or total loss of vision.

Voice Input

Software that recognizes voice commands, and responds accordingly.

Voice Output

Computer programs that read the screen to a user.

Voice Recognition

Programs that recognize a person's voice and its various characteristics. Closely related to Voice Input.

Voice Recognition Software

Software that can be trained to recognize a person's voice, and either execute commands, or turn the voice into text or other forms of media such as sign language for the deaf.

Voice XML

 A type of XML that allows the user to interact with a web page using Voice Recognition software.

WAVE

The WAVE is an accessibility tool originally written by Dr. Len Kasday at Temple. It helps people perform design tasks that require human judgment (e.g. "Does this ALT text provide a functional equivalent for this image?" "Does this reading order make sense?". Visit the WAVE site for more information.

Web Accessibility Initiative (WAI)

 Started by W3C and its members in 1997, this initiative addresses web accessibility issues. Visit the WAI site for more information.

Web Content Accessibility Guidelines (WCAG)

 These are the guidelines built by the W3C WAI to address issues in building accessible web pages. Visit the Web Content Accessibility Guidelines 1.0 site and the Web Content Accessibility Guidelines 2.0 site for more information.

Web Standards

    The term Web Standards refers to the World Wide Web Consortium's (W3C) specifications and guidelines. It means the full support the W3C recommendations for XHTML, CSS, and the DOM/ECMA Script (among others like XML, SVG, and MathML). Complying with web standards is using these technologies according to W3C specifications.
    Most assistive and adaptive technologies are based on W3C standards. Error-free, well-formed, standards-compliant HTML is the foundation of an accessible Web site. Standards compliance is an essential ingredient for a higher level of accessibility, portability platform independence, conversion to XML, reusablity and forward compatibility. In itself following web standards, does not guarantee that a page is semantically meaningful, structurally sound, or accessible.
    Standard and valid (X)HTML and CSS is the base to start from. Semantically rich, well structured, accessible documents that validate are the goal. Following standards, especially in terms of creating structured, valid markup and removing presentational elements and attributes makes a document inherently more accessible. The future of the web as laid out by the World Wide Web Consortium is based on two underlying concepts. These rwo concepts are the heart of Web Standards. They are:
       1. Separating content and presentation.
       2. Semantically meaningful markup (Good document structure).
          For more information visit The Web Standards Project's Frequently Asked Questions.

Website

A website is a related group of web pages published on the World Wide Web.

Well-Formed

 A well formed XML document follows the rules set forth by the XML specification, including having all tags closed, all attributes quoted, a XML declaration, correct comments etc.

While Structure

In programming, a while structure continues to loop while an expression is true. It evaluates a Boolean expression. If the expression is false, the code inside the braces is skipped over. If true, the code within the braces is executed. When the close brace } is reached, the test condition is reevaluated, and if it evaluates to true, the code in the loop is re-executed. This continues until the condition is met. Note that the condition is only tested at the beginning of each iteration, so even if the truth of the condition changes during the middle of the code block, the code will be executed to the end.

White Space

White space, also known as negative space, is the open space between visual elements on a web page. The term describes the unused areas. White space gives the eye rest. Cluttered designs hinder clarity and tire the eye. Judicial placement of white space can emphasis page elements and help to direct the eye. You shouldn't use HTML to create whitespace. Use cascading style sheets for this purpose.

Wireframe

 A wireframe is a skeleton version of a website that depicts navigational concepts and page content. It is a set of cross-linked pages that acts like a functional prototype of the final website without the graphics. A wirefraame often has only sketchy text content. It is often accompanied by a tree diagram or flowchart of the website. It doesn't take into account visual design or page layout. For more information see: Wireframes.

Wireless Application Protocol (WAP)

 A specification that allows users to access information via wireless handheld devices. These devices usually have small screens.

World Wide Web Consortium (W3C)

 An international consortium of companies and organizations involved with the Internet and the World Wide Web, responsible for maintaining web technology standards, such as HTML and CSS. It was "created in October 1994, to lead the World Wide Web to its full potential by developing common protocols that promote its evolution and ensure its interoperability." Visit the W3C site for more information.

Your Mileage May Vary

 A disclaimer often found in freeware and elsewhere.

Zip

Zip is a compressed file format for windows operating systems.