Definition & Meaning of "sea change"

What is the origin of the idiom "sea change" and when to use it?

The idiom "sea change" originates from Shakespeare's play "The Tempest," where Ariel sings, "Full fathom five thy father lies; Of his bones are coral made; Those are pearls that were his eyes: Nothing of him that doth fade, But doth suffer a sea-change." In the play, it signifies a transformation brought about by the sea, specifically the change of a human body into something different, like coral or pearls. Over time, this phrase has evolved and is now used to describe a profound, significant, or transformative change in various contexts, often related to a person's character, a situation, or a society.