HTML Heading Tag
Heading tags are defined from <h1> to <h6>.
In heading tag <h1> is the largest size while <h6> is the smallest size.
Heading tags default font size can be changed using CSS.
All global attributes are supported.
From HTML 5 the align attribute is obsoleted, so don't use it, instead use text-align property in CSS to align elements.
You should use heading tags for headings only. Don't use heading tags to change text size.