Imagery makes something stand out and speaks to our emotions
Like all of William Shakespeare’s plays, Macbeth is full of imagery. Most of the imagery is based on simple dualism such as day/night, good/evil, man/nature, and order/chaos. This makes sense since the play is about a good man who does something truly evil. Many of the images have been taken from fields such as war, religion, nature, animals, clothes, and sickness.
Concerning the specific types of imagery, Shakespeare uses an enormous number of metaphors and a smaller number of similes and personifications.
Imagery can have many functions, but one is making the text come alive to us. Sometimes a metaphor just explains something more clearly. Imagery also appeals to our emotions in a way that plain language cannot.