The phrase "what in the world" is an idiomatic expression used to emphasize surprise, shock, anger, or disgust. It is often used in the form of a rhetorical question to express bewilderment or disbelief about a situation. The phrase is not meant to be taken literally, but rather as an exclamation to convey strong emotions. For example, "What in the world is going on here?" expresses surprise or confusion about a situation. The emphasis on "in the world" serves to intensify the feeling of incredulity or amazement. This idiomatic expression is commonly used in informal language to convey strong emotions or reactions to unexpected or puzzling events.