What is whew?

"Whew" is an informal interjection in the English language used to express relief, amazement, or exhaustion. It's often used in response to a situation that was intense, stressful, or narrowly avoided. The expression conveys the sense of letting out a breath, which metaphorically signifies the release of tension. For example, someone might say "whew" after narrowly avoiding an accident or after completing a long and arduous task.