"Italic" is used as an adjective to describe something that is in italics.
* Example: "The book title was written in *italic* type."
"Italics" is used as a noun to refer to the style of type itself.
* Example: "Please use *italics* for the book titles."
Here's a breakdown:
* Italic (adjective): Describes something that is set in italics.
* Italics (noun): Refers to the style of type itself.
So, whether you use "italic" or "italics" depends on whether you're describing something that is in italics or referring to the style of type itself.