An XHTML is a latest HTML standard. XHTML is the reformulation of HTML 4.01 in the XML. Writing pages to the latest HTML 4.01 standard will do bring as close as possible you to latest XHTML standard.

By Using the Cascading Style Sheets (CSS) is a preferred way of separating the content from the style in the quality web pages. By using the CSS you can do store all the information about the style of the web pages in a single document.

All the modern web browsers have the support for both CSS 1 and CSS 2 standards. Using CSS will do improve the quality of the web site and increases the readability for many of the different browsers. It will also do greatly reduce a web site development osts..

Web validator is a software program which can do check the web pages against a web standards. When you use the validator to check an HTML, XHTML or CSS document, the validator will return the list of any errors which were found , according to the chosen standard. Normally a validator will also returns the line numbers where errors is found. Make sure to make it a habit to validate all the web pages before the publishing them.

WAI stands for "Web Accessibility Initiative", and is an initiated by W3C. WAI coordinates with the organizations around the world to increase the accessibility of the Internet through is the six primary areas of work: the technology, guidelines, tools, research, education and the development.

You can improve quality of the web site, and make information available to more and more people (and the browsers) by writing the web pages according to the WAI guidelines. You will learn more about the WAI in the later chapter of this tutorial.