Cascading Style Sheets
Web design is an evolving medium. Practices once considered standard are now deprecated, and eventually will become obsolete as web standards are redefined. For this reason I have decided to use CSS for section 2 on web design.
To explain further; page design can, generally speaking, be accomplished in one of two ways; using layout tables or using CSS layers. Tables were introduced with Netscape1.1 and have been used to layout webpages since the very first days of the web. HTML was never designed to layout pages, however, and a number of hacks, or workarounds were needed to get pages to display properly. While pages displayed correctly, they were inaccessible to people with disabilities as screen readers couldn't read the content stored inside tables, and pages were hard to update and edit.
To address these limitations the Web Standards Consortium introduced CSS in 1996. It is a presentation language for HTML. To use it you link a CSS style sheet to your HTML page, and the CSS code formats and lays out the content of the page. CSS has been used for some time to format text (Define its size and colour etc.), but the more advanced CSS2, which adds the ability to add layers to an HTML document (emulating a layout table) was not commonly used, as the CSS2 specification was not properly implemented on many popular web browsers (particularly Netscape 4) and so pages would not display properly.
However, as browsers are upgraded the CSS2 specification is more correctly implemented, and most of the latest browsers will display pages correctly. In particular the Firefox and Opera browsers have made a point of implementing complete and accurate CSS2 specifications.
While students need to understand tables and table-based layout, CSS will increasingly become the way in which web pages are laid out, as the presentation technology of CSS is far more powerful than that of HTML alone.