HTML heading is used to specify web page heading and sub heading.HTML heading is defined with
<h1> is used for most important heading while
<h6> used for least important heading.
Important Of HTML Heading
HTML headings are very important during the indexing of the website.HTML heading
<h1> specifies the main heading of the page while
<h2> specifies the subheading of the page and another heading specifies least important.
Changing Font Size Of The Heading
Please keep in mind that all the heading tag has it's by default font size. The font size of the heading tag could be changed by using CSS style properties.
Please keep in mind that font size gradually decreases from h1 tag to h6 tag.