What is CSS Cascading Style Sheets?

Further information on the different selector types and on the CSS syntax can be found in our detailed CSS tutorial. You can create an appealing website design with the MyWebsite Website Builder, thanks to professional design templates. Choose from a wide range of templates and find a style that works for you in just a few clicks.

css definition

Specifies that the element selected by B is located within the table column specified by A. Elements which span multiple columns are considered to be a member of all of those columns. Specifies that the elements selected by both A and B share the same parent and that the what is css element selected by A comes before—but not necessarily immediately before—the element selected by B. Specifies that the elements selected by both A and B have the same parent and that the element selected by B immediately follows the element selected by A horizontally.

CSS Syntax

With a simple change of one line, a different style sheet can be used for the same page. This has advantages for accessibility, as well as providing the ability to tailor a page or site to different target devices. Furthermore, devices not able to understand the styling still display the content. This further decouples the styling from the HTML document and makes it possible to restyle multiple documents by simply editing a shared external CSS file. For example, headings (h1 elements), sub-headings (h2), sub-sub-headings (h3), etc., are defined structurally using HTML. In print and on the screen, choice of font, size, color and emphasis for these elements is presentational.

css definition

In each example above, everything before the first curly brace is an attribute selector. We’d recommend you learn HTML first and then check out a course on learning CSS. Because CSS is used with HTML in various ways, a solid understanding of HTML is required before you can jump straight into altering HTML elements using CSS. But as you’re developing a web page, and you want to modify a single element, you could use inline CSS. In another scenario, if there’s a bug on a website and you need to fix it fast, inline CSS could be the ticket — that is, until you can go back in later and fix the issue more globally with external CSS.


CSS is a rule-based language — you define the rules by specifying groups of styles that should be applied to particular elements or groups of elements on your web page. CSS can be used for very basic document text styling — for example, for changing the color and size of headings and links. It can be used to create a layout — for example, turning a single column of text into a layout with a main content area and a sidebar for related information. Have a look at the links in this paragraph for specific examples.

The best practice for CSS is to save it as a .css file, separate from your .html file. When you find a style that you like, you can apply it to as many pages as you’d like. CSS, just like HTML, is one of the core languages of the World Wide Web.

Element Type Selector

A keyword is a value for a property and is somewhat like a reserved word for a particular property. Different properties have different keywords, and all properties allow the keyword “inherit”. In HTML, a page will have validation errors if two or more elements share the same ID.