Bringing two different things close together with an explicit word, such as "like," "just as," or "seems." Unlike the metaphor, the comparison makes plain that they are two things.
In Macbeth
now does he feel his title / Hang loose about him, like a giant's robe / Upon a dwarfish thief
Angus compares Macbeth’s title to "a giant’s robe upon a dwarfish thief," with the word "like." The comparison shows that the title "hangs loose" because it was never made for him: the office is bigger than the person.