HTML ID

The id Attribute: The id attribute specifies a unique id for an HTML element (the value must be unique within the HTML document). The id value can be used by CSS and JavaScript to perform certain tasks for the element with the specific id value. In CSS, to select an element with a specific id, write a hash (#) character, followed by the id of the element

<style>
#myHeader {
  background-color: yellow;
  color: black;
  padding: 40px;
  text-align: center;
}
</style>

<h1 id="myHeader">My Header</h1>

Difference Between Class and ID: 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

<style>
/* Style the element with the id "myHeader" */
#myHeader {
  background-color: yellow;
  color: black;
  padding: 40px;
  text-align: center;
}

/* Style all elements with the class name "city" */
.city {
  background-color: green;
  color: white;
  padding: 10px;
}
</style>

<!-- 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>

Bookmarks with ID and Links: HTML bookmarks are used to allow readers to jump to specific parts of a Web page. Bookmarks can be useful if your webpage is very long. To make a bookmark, you must first create the bookmark, and then add a link to it. When the link is clicked, the page will scroll to the location with the bookmark.

<h2 id="C1">html </h2>