server side (i.e. PHP) vs. client side
element vs. tag - the tag is "<h2>" and the element is just the "h2", so whatever is inside the brackets.
inline text element (semantic vs. presentational) - everything that is within the text
	semantic - describes the meaning of text i.e. <code>, <strong>, <em>, <abbr>
	presentational - describes how the text looks like i.e. CSS - cascading style sheet
empty element - things the browser does not recognize in code i.e. line breaks, empty spaces