what’s up 禮貌嗎？

What's the meaning behind 'What's up' in a polite context?

The phrase 'What's up?' can be considered casual, and it might depend on the context and the relationship between the speakers. In informal settings, it usually serves as a friendly greeting or a way to initiate conversation. However, in formal situations, opting for a more traditional greeting may be more appropriate. Ultimately, the politeness of the question hinges on the tone and familiarity between the individuals involved.