Semantic portal
The id Attribute: Difference Between Class and ID
Difference Between Class and ID
<!-- A unique element -->
<h1 id="myHeader">My Cities</h1>
<!-- Multiple similar elements -->
<h2 class="city">London</h2>
<p>London is the capital of England.</p>
<h2 class="city">Paris</h2>
<p>Paris is the capital of France.</p>
<h2 class="city">Tokyo</h2>
<p>Tokyo is the capital of Japan.</p>An HTML element can only have one unique id that belongs to that single element, while a class name can be used by multiple elements.