A CSS class , an attribute used to define a group of HTML elements in order to apply unique styling and formatting to those elements with CSS.
Example :
<!DOCTYPE html>
<html lang="en">
<head>
<title>class Selector</title>
<style>
.intro {
background-color: yellow;
color: red;
font-weight: bold;
}
</style>
</head>
<body>
<h1 class="intro">Welcome to my Web</h1>
<p>Bio-Data</p>
Name: OnWeb Sharma G <br>
Class: PGDCA <br>
Subject: Computer Application <br>
<p class="intro">Address: Mainpuri, Uttar Pradesh</p>
</body>
</html>Show Output
