CSS stands for Cascading Style Sheets. It’s the language used to control how a webpage looks — colors, fonts, spacing, layout, and everything visual.
If HTML builds the structure of a page, CSS is what makes it presentable. Without CSS, every website would look like plain, unstyled text on a white background.
A Quick Example
CSS works by targeting an element and describing how it should appear. For example:
p {
color: #333333;
font-size: 16px;
}This rule tells the browser to make every paragraph dark gray and 16 pixels in size. Rules like this are what give a website its visual identity.
Where CSS Lives
CSS can be written directly inside an HTML file, but it’s more commonly kept in a separate stylesheet file and linked to the page. This keeps content and design cleanly separated, which makes both easier to maintain.
In WordPress, most of this styling comes from your theme, though many themes and plugins also let you add custom CSS through the site editor without touching any files directly.
Why “Cascading”?
The name comes from how CSS rules “cascade” — when multiple rules could apply to the same element, CSS follows a clear set of priorities to decide which one wins. This is what lets you set a general style for your whole site, then override it for specific sections when needed.