Example of Italicized

Italicized words are used for various purposes in text:

Emphasis: The text is being highlighted because of its significance.
Reference: Proper names of subjects are sometimes italicized to identify them and make them stand out.
Convention: In many forms of literature, italicized items are common usage. In old indexes, for example.
Scientific: Many scientific texts italicize the full scientific names of subjects.

Examples of Italicized:

(In context with types of text)

Emphasis: They said they were going to sell!
Reference: Trevelyan's Social History of England is an important work in this area.
Convention: Ibid, pp 227-229
Scientific: Tyrannosaurus Rex may not have considered Ankylosaurs worth hunting.
https://en.wikipedia.org/wiki/Italic
https://en.wikipedia.org/wiki/Italic_type