What is CSS?

CSS and html code on computer screen

If web design and web development are disciplines you’re interested in, then you can expect Hypertext Markup Language (HTML) to be the first tool in your belt. This language defines the structure and content of a web page by using tags that designate elements such as your headings, paragraphs, and images. HTML is the foundation for the world wide web and it’s closely followed by a programming language that’s just as capable, useful, and important to the art of web design: Cascading Style Sheets, or CSS.


When answering the question, “What is CSS?” it’s important to understand its relationship with HTML. At its core, it is an organizer for the elements HTML has designated on a web page. So, if HTML is used to determine that a web page will be made up of several paragraphs, a few headings, and some images, it can then determine how all these elements are to be presented — how the content is laid out, looks, and reacts. These functions are known as CSS properties. These properties also define the finer details, including an element’s color, size, font, and border.


CSS provides web developers with two essential web design benefits: simplicity and efficiency. It simplifies the design process by separating the content and presentation layers of a web page. This ensures developers can create reusable styles that can be applied to multiple pages, which reduces the amount of code required. Think of it like a copy/paste function for styling! One of the most appreciated qualities of CSS is that it can be implemented with only a few lines of code. This keeps  files relatively small and light, which coincidentally causes less stress on loading times.


We now know HTML and CSS go hand-in-hand. But how exactly is it applied to HTML? CSS can be written through a text editor or word processor in regular text with simple commands. They are then saved as CSS files (.css) and applied externally, internally, or inline:

  • Internal CSS is defined within an HTML document using a <style> tag. This file will only apply to the HTML document in which it was defined. This type of use is especially useful when a CSS property is only needed on one page.
  • External CSS is defined separately with a .css extension that is then linked to an HTML document using a <link> tag. Unlike internal CSS, it is applied to multiple HTML documents, which makes it easier to maintain consistent styles across an entire website.
  • Inline CSS is defined directly into HTML code using the style attribute. This type of CSS strictly applies to the element in which it is defined and is generally used for one-off changes or to override styles within internal or external CSS.

Gain the Skills for a Tech Career

Whether you envision a future in web development or want to try your hand at user experience (UX) design, learning to use CSS is essential. In a Kenzie Academy program from Southern New Hampshire University, you can go through the process of gaining the skills and knowledge needed to begin your tech career. You can start with the basics of CSS, HTML, JavaScript, and other tech fundamentals, advance your knowledge as you learn detailed concepts, and create relative experience through projects that simulate real-world environments.

Feeling overwhelmed by the prospect of a tech career? We have a tool that can introduce you to tech with a fun, interactive approach and can help put your mind at ease. Kenzie Free is 3 coding classes that teach you HTML, CSS, and JavaScript through video tutorials. You’ll learn as you go and build a project of your own, so make sure you complete each class in order. Overcome your tech intimidation and begin Kenzie Free today.

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