HTML Id attributes starts with hash ( # ) in CSS. We can use this attribute to style any element in html.
Below is the simple example of using “id” attribute for styling paragraph.
<!DOCTYPE html>
<html>
<head>
<style>
#exampleId1 {
background-color: red;
font-size:20px;
}
</style>
</head>
<body>
<p id="exampleId1">Para1 - This paragraph is styled with id "exampleId1"</p>
</body>
</html>
When we run this code in browser, we can see the page as,