HTML has a limited number of tags, but sometimes you need to differentiate between specific elements. For example, if you want to apply different styles to various paragraphs (<p> elements), you can use the class and id attributes.

The class attribute assigns a class to a specific HTML element. Multiple elements can share the same class. This allows you to apply the same styles to multiple elements.

In this example, two paragraphs share the same highlight class, allowing you to apply the same styles to both.

The id attribute assigns a unique identifier to a specific HTML element. Unlike the class attribute, each element can only have one unique id. This is useful for applying styles or manipulating a specific element using JavaScript.

It's important to remember that the id must be unique on the page. You cannot use the same id value for multiple elements.