What Is Italic vs Oblique?
Italics are slanted letterforms used for emphasis, titles, and quotations. A true italic is redrawn with cursive, calligraphic shapes — the "a" and "f" often change form. An oblique is simply the upright design mechanically slanted. Serif faces usually have true italics; many sans-serifs use obliques.
True italics descend from Renaissance handwriting and have their own rhythm, so they read as a distinct voice rather than a tilted copy of the roman.
Faux italic — software slanting an upright font — skews every curve uniformly and looks crude. Prefer a designed italic or oblique that ships with the family.