What is CSS?

• CSS stands for Cascading S tyle Sheets
• CSS describes how HTML elements are to be displayed on screen, paper, or in other media
• CSS saves a lot of work. It can control the layout of multiple web pages all at once
• External stylesheets are stored in CSS files

A CSS rule-set consists of a selector and a declaration block:

The selector points to the HTML element you want to style.

The declaration block contains one or more declarations separated by semicolons.

Each declaration includes a CSS property name and a value, separated by a colon.

Multiple CSS declarations are separated with semicolons, and declaration blocks are surrounded by curly braces.

CSS selectors are used to "find" (or select) the HTML elements you want to style.

We can divide CSS selectors into five categories:

• Simple selectors (select elements based on name, id, class)
• Combinator selectors (select elements based on a specific relationship between them)
• Pseudo-class selectors (select elements based on a certain state)
• Pseudo-elements selectors (select and style a part of an element)
• Attribute selectors (select elements based on an attribute or attribute value)

This page will explain the most basic CSS selectors.

When a browser reads a style sheet, it will format the HTML document according to the information in the style sheet.

Three Ways to Insert CSS

There are three ways of inserting a style sheet:

• External CSS
• Internal CSS
• Inline CSS

Comments are used to explain the code, and may help when you edit the source code at a later date.

Comments are ignored by browsers.

A CSS comment is placed inside the <style> element, and starts with /* and ends with \ */: