CSS full form is Cascading Style Sheets.
CSS is the language we use to design the HTML tags.
CSS (Cascading Style Sheets) is used to apply styles to web pages.
The below example show how HTML Elements design with the help of CSS.
<!DOCTYPE html>
<html>
<head>
<style>
body {
background-color: aliceblue;
}
h1 {
color: green;
text-align: center;
}
p {
font-family: verdana;
font-size: 16px;
}
</style>
</head>
<body>
<h1>This is Heading</h1>
<p>This is paragraph.</p>
</body>
</html>