CSS: What it is & why we use it
cascading style sheets defined
Cascading Style Sheets, usually just called CSS for short, are a means of seperating the content of a document from the presentational elements such as: colors, fonts, layout, etc... This has numerous benefits in Web development such as simplifying and reducing the size of the html file and allowing the content to be displayed correctly in different formats such as in print or on the screen. Perhaps the most valuable attribute of a CSS controlled site is the ability to make site wide changes, even if there are tousands of individual pages, by simply making a change to the style sheet.
So exactly what sort of things do style sheets control? Well...the possibilities are really endless, but some of the more common thing which are handled through style sheet definition include:
- The size and background color (or even background image) for a page
- The font type, size, and color of text
- How text is aligned, spaced, etc...
- How and where images appear on the page
- Placement and other formatting of various sections
- How links look and behave
- Plus a whole lot more!
Through the use of CSS, it is possible to have a single web page file appear and behave differently depending on if it is being accessed by such different devices as: a computer monitor screen, a scree reader program for the blind, or being sent to a printer. By having the content handled correctly by these different devices, CSS greatly improves the accessibility and functionality of a site.