h2

The h2 HTML element represents a heading for the section with which it is associated.

<h2 attribute-name="attribute-value"></h2>

Global

h2 {
    display: block;
    font-size: 1.5em;
    font-weight: bold;
    margin: .83em 0 .83em 0;
}

h1

h3

h4

h5

h6

Web Hypertext Application Technology Working Group (WHATWG)