Understanding the Correct Use of HTML Header Tags

HTML, or HyperText Markup Language, is a standard language used to create and design websites. One fundamental aspect of HTML that every web developer should be familiar with is the use of header tags.

In HTML, header tags are used to define headings, with

being the highest level, and

being the lowest. These tags not only affect the size and boldness of your text, but also play a vital role in your website's SEO (Search Engine Optimization).

The correct answer to the quiz question "Which of the following HTML tags is not valid?" is <h8>. In HTML, the headline elements range from <h1> to <h6>, with <h1> producing the largest text size and <h6> producing the smallest. Therefore, <h8> doesn't exist in HTML and is not a valid tag.

Here is an example of using HTML headline tags in a practical context:

<h1> This is a Headline 1 </h1>
<h2> This is a Headline 2 </h2>
<h3> This is a Headline 3 </h3>
<h4> This is a Headline 4 </h4>
<h5> This is a Headline 5 </h5>
<h6> This is a Headline 6 </h6>

When utilizing HTML headers, it's crucial to consider their hierarchy. <h1> should be used as the main title or header of a page (you should only have one <h1> per page for SEO purposes). Following that, <h2> can be used for subheadings, <h3> for sub-subheadings, and so on, down to <h6>.

However, while the header tags from <h1> to <h6> are valid in HTML, <h8> is not. Always ensure that you're using the correct header tags to structure your content effectively and boost your SEO rankings.