Chesterhouse School ICT Course (Grade 10 and 11)

Click here for an introduction to CSS. The benefits of CSS are Fast download time CSS downloads faster than tables because: * Browsers read through tables twice before displaying their contents, once to work out their structure and once to determine their content * Tables appear on the screen all in one go - no part of the table will appear until the entire table is downloaded and rendered * Tables encourage the use of spacer images to aid with positioning * CSS generally requires less code than cumbersome tables * All code to do with the layout can be placed in an external CSS document, which will be called up just once and then cached (stored) on the user's computer; table layout, stored in each HTML document, must be loaded up each time a new page downloads * With CSS you can control the order items download on to the screen - make the content appear before slow-loading images and your site users will definitely appreciate it More accessible The number of users browsing the web through handheld devices is growing massively. In 2008 alone an estimated 58 million PDAs will be sold (source: eTForecast3) and one third of the world's population will own a wireless device (source: ClickZ4). You can make an additional CSS document specifically for handheld devices, which will be called up in place of the regular CSS document. This is not possible with a tabular layout. More search engine-friendly Search engines can often spider CSS-driven web pages more easily as they usually have simpler, better structured HTML code. The search engine can then make a more educated guess as to what the web page is about, so all other things being equal, your web pages will appear higher in the search rankings with a CSS layout. Print-friendly When a user chooses to print a web page an alternative CSS document can be called up. This document can specify that formatting, images and navigation disappear and just the page content appear on the printed version.