HTML (Hypertext Markup Language) is the primary technology used in the development of simple web sites. HTML provides a simple tag-based syntax for creating forms, embedding pictures and links, and producing other structural and presentational aspects of a web page. Each tag can contain attributes that further refine the meaning of the tag. For more information, see Wikipedia or the HTML specification.
XHTML (Extensible Hypertext Markup Language) is almost identical HTML with the exception of a stricter set of syntactic rules based on the XML standard. For instance, in HTML you can use an opening tag in many instances without a matching closing tag. In XHTML each opening tag must have a matching closing tag. For further reading, see Wikipedia or XHTML2 Working Group Home Page.
There are numerous tools for validating that correct HTML or XHTML syntax is used on your web site, however, even if the syntax is conformant, browser compatibility issues affect how the code is rendered. It is not unusual to see the same web page rendered differently across various browsers and browser versions. This is why cross-browser compatibility testing is so important.
DHTML (Dynamic HTML) is a collection of technologies used to move beyond the static presentation of information to create more interactive web pages. Technologies that play a role in DHTML include HTML, JavaScript, Cascading Style Sheets (CSS), and the Document Object Model (DOM). CSS is used to control the presentation of the structured content defined by HTML. The DOM is a client-side programmable interface to the state of the HTML document being rendered and its associated CSS presentation. The Dynamic part of DHTML comes into play when JavaScript is used to manipulate the state of the DOM to cause the appearance or behavior of the rendered web page to change. See Wikipedia or HTML and DHTML Reference on MSDN for more information.
Testing a web page that uses DHTML is similar to testing a desktop application in that user interactions in one area of a page may have an impact on the presentation or behavior of other parts of the page, all without a return trip to the server.
QualityLogic has extensive experience in validating the code, rendered pages, and behaviors included in your web site. Explore QualityLogic’s website testing solutions by clicking on the links under "Testing Solutions" to the right, or contact us for more information or to request a quote.