Css media

What is CSS? Here’s what you need to know

  • CSS is a programming language that allows you to customize the color, font, and layout of an HTML coded website.
  • CSS adds vibrancy to the online experience, because without it, websites would look like identical bland lines of text and images.
  • There are three distinct CSS styles that you can use when designing your website.
  • Visit Insider’s Technical Reference Library for more stories.

Even if you are not familiar with the term itself, CSS is a component of website coding that every internet user has experienced.

While you might not know exactly what CSS is, it’s something to embrace – CSS is dramatically enriching the online ecosystem.

Here’s everything you need to know about how CSS works, its benefits and importance.

What is CSS?

CSS, or Cascading Style Sheets, is an encoding language used to add colors, layouts, and fonts to a website.

If you were an early internet user, your first impression of web design might have been quite disappointing. This is because CSS was not used by browsers until 1996.

CSS is not the content of a website, but its visual presentation. Think of it this way: CSS is the style and HTML is the substance.

1_ _What_is_CSS

CSS adds design elements to a web page.

Emma Witman / Insider


HTML serves as the foundation of a site by encoding all the content that you are there to consume it, but without CSS the website would be just a jumble of words and images.

Insider homepage without CSS

Without CSS, the Insider homepage appears without much stylistic flow.

Emma Witman / Insider


You may also be familiar with JavaScript, the third pillar of website development. Java is a language that, unlike the static styling elements added by CSS, allows you to code in complex interactive content. When it comes to web design, CSS is the most crucial element of web development.

Types of CSS styles

  • Internal CSS: Also known as the “built-in” style, internal CSS requires coding the CSS tag in the section of every page you code – the style will not be applied to an entire website. There are benefits though, as you’ll also be creating a standalone, easily previewable template for sharing.
  • External CSS: This is often considered the easiest method for the long term maintenance of a website. All of your CSS coding is done in a separate CSS file and then applied to any page of your choice. Site load times could also benefit from the external styling.
  • CSS online: This style is slightly more intensive for coders, requiring each individual HTML tag to be styled. This can also be useful for minor changes and quick previews of changes.

Benefits of CSS

  • The coding language of CSS is simple, but customizable to a huge degree.
  • Formatting through CSS makes it easier to navigate websites by placing buttons in logical places that make them more likely to get clicks.
  • CSS can also avoid having to use so many lines of code, allowing pages to load faster.
  • CSS’s responsive design elements make the language suitable for presentation on any size screen, from a mobile phone to a desktop.

Why CSS is important

CSS has created a unified standard for web page design that makes the process more accessible.

It’s probably best known for its user-friendliness – a coding language that shouldn’t intimidate anyone.

With CSS, a crisp looking website can be achieved without hiring an expert coder.