Strong is used to indicate strong importance.
This text has added emphasis.
The b element is stylistically different text from normal text, without any special importance.
The i element is text that is set off from the normal text.
The u element is text with an unarticulated, though explicitly rendered, non-textual annotation.
This text has a strikethrough.
Superscript®.
Subscript for things like H2O.
This small text is small for for fine print, etc..
Abbreviation: HTML.
This text is a short inline quotation
.
This is a citation
The mark element indicates a highlight.