Emphasis, as the term is used here, is the use of typographical effects to call attention to text. These effects can include italics, bold, all-caps, quotation marks, color, and so on. Emphasis attracts the attention of the reader—or “cues” them—to actions they must take or to information they must consider carefully.
Practically any special textual effect that is different from regular body text can function as an emphasis technique. Things like italics, bold, underscores, caps, different size type, alternate fonts, colour, and more can act as emphasis techniques.
However, if emphasis techniques are used in excess, readers can become reluctant to read a text and may avoid it altogether because it is too busy or distracting. NOTICE HOW UNREADABLE THIS SENTENCE IS BECAUSE TOO MUCH EMPHASIS IS USED. When it comes to emphasis, there can be too much of a good thing! Emphasis techniques must be used strategically and consistently.