The abbreviation "wbu" stands for "what about you?" It is commonly used in casual conversations, particularly in text messaging and online chats. It is a way to ask someone for their opinion, feelings, or situation after sharing your own.
The phrase "what about you?" has its roots in English, where "what" refers to asking for information, "about" indicates a topic of discussion, and "you" signifies the person being addressed. The abbreviation "wbu" emerged with the rise of informal digital communication in the early 21st century.