What is CSS?
CSS, or Cascading Style Sheets, go hand-in-hand with HTML. They’re responsible for telling your computer how it should style the layout of your HTML file.
There are endless options to style your website with CSS – these stylesheets cover everything from colours, fonts and backgrounds, to transitions and beyond.
CSS is made up of selectors – they tell the computer which HTML element it is talking to. Inside these selectors, we list CSS properties, which are comprised of a name and a value. Which will look a little something like this:

We say that HTML and CSS go hand-in-hand, because every HTML element you create needs to have a corresponding CSS property. A good analogy is:
‘HTML is WHAT you’re saying, and CSS is HOW you’re saying it – one is just as important as the other’.