This virtual character formatting element indicates text that
should be emphasized. It is usually rendered as italic text.
This is a basic HTML element that all browsers should support in some fashion.
Many people use this interchangeably with the I (Italic) element. If the
aim is to place emphasis on a passage of text, EM is the preferred
element to use - If the aim is only to explicitly italicize, then use
I.
Text based or some other types of browsers may not be able to
render the I element, but the EM element implies that the contained
text should be brought to prominence in some manner.