What is CSS?

Normal HTML allows you to specify the color and size of text using formatting tags. If you need to change the parameters of the same items on the site, you'll have to browse all the pages to find and change tags.

Cascading Style Sheets (CSS) allow you to store color, text sizes and other parameters in styles. A style is a set of formatting rules that apply to a document element to quickly change its appearance.

Styles allow one action to apply at once the entire group of formatting attributes. With their help you can, for example, change the appearance of all headings. Instead of formatting the header in three steps, when you first set its size, then the font "Arial" and, finally, center alignment, you can do the same thing at the same time by applying the style to the <H1> tag. If you want to quickly change the appearance of text created with one of the styles, it is enough to change the style settings in all documents where it is used, and the text type will change automatically.

Another advantage of CSS is that styles offer much more formatting options than plain HTML. In addition, the styles can be stored in an external file, the browser caches such documents, so the site will load up a little faster.

CSS is a powerful system for website developers, expanding their capabilities in the design and layout of web pages. In the scientific environment, where the WWW technology came from, people were more concerned with the content of documents than with their design, but for most people the presentation of the site, the way it looks, plays a more important role. HTML restrictions have spawned a lot of techniques for creating web pages, such as:

• Use of various HTML extensions;
• Applying images instead of text;
• The use of drawings to control the empty space, the so-called spacers;
• The use of tables for the layout of web pages;
• Writing software scripts instead of using HTML.

These techniques significantly increase the complexity of developing web pages, offer limited flexibility in their creation and management, and also create difficulties for people who do not own them.

Styles solve these problems while at the same time replacing only a limited area of ​​the HTML representation mechanisms.