XOR gate

Headings in HTML are similar to headings in other types of media. In newspapers large headings are often used to capture a reader’s attention. Headings are also used to describe content, like the title of an article.
In HTML we take a similar approach. In HTML there are six different heading elements. Headings can be used for a variety of purposes, like titling sections, articles or other forms of content.
Here is a list of the heading elements available in HTML. They are ordered from largest to smallest in size:

<h1> — used for main headings. All other smaller headings are used for subheadings.
<h2>
<h3>
<h4>
<h5>
<h6>
The following example code uses a headline intended to capture a reader’s attention. It uses the largest heading available, the main heading element:
/* ]]> */