Check out example codes for "class in html". It will help you in understanding the concepts better.
Code Example 1
<ul class="legend">
<li><span class="greendot"></span>Text</li><br></br>
<li><span class="yellowdot"></span>Text</li><br></br>
<li><span class="reddot"></span>Text</li><br></br>
<li><span class="blackdot"></span>Text</li><br></br>
</ul>
Code Example 2
<p class="ThisIsAClassName">HI</p>
Code Example 3
<p class="ClassExample">ClassExample!!</p>
Code Example 4
<!-- in the head element -->
<style> h1 { color:blue; } </style>
<!-- in the body element -->
<h1> text in blue because all "h1" element is in blue </h1>
Code Example 5
<h1 class="write a name">H1 content</h1>
Code Example 6
<!DOCTYPE html>
<html>
<head>
<style>
.city {
background-color: tomato;
color: white;
border: 2px solid black;
margin: 20px;
padding: 20px;
}
</style>
</head>
<body>
<div class="city">
<h2>London</h2>
<p>London is the capital of England.</p>
</div>
<div class="city">
<h2>Paris</h2>
<p>Paris is the capital of France.</p>
</div>
<div class="city">
<h2>Tokyo</h2>
<p>Tokyo is the capital of Japan.</p>
</div>
</body>
</html>
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