Let’s start with a simple HTML page which will illustrate the HTML5 changes; I will use an example for the demand & supply curves, just displaying a table and a chart picture.
Every SGML document (from which the HTML format is extended) starts with a DOCTYPE declaration, which associates it with the appropriate Document Type Declaration (DTD).
An XHTML1.0 (the latest HTML standard before HTML5) page has a declaration like this:
<!--DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
This is the HTML5 doctype:
That’s it. Just 15 characters. Already a nice change.