Difference between How are you/how are you doing/what are you doing/what do you do?

How are you?                      what are you doing?

The two phrases ‘How Are You’ and ‘How Are You Doing’ are commonly used as part of a greeting.

It is generally considered that ‘how are you’ is a more formal and reserved greeting than ‘how are you doing.’ ‘How are you doing’ is mainly used more in a more laid-back setting with people who are familiar to the speaker.

‘How are you’ is generally asked while referring to one’s health or feelings. 

‘How are you doing’ on the other hand, can be used interchangeably in the previously stated instances, such after a difficult period, one may ask ‘how are you doing’ or ‘how are you doing now.’ Whereas, ‘how are you doing’ can also be used to refer to the status of oneself, such as, while referring to work, life or the status of a project or report, etc.

Examples:

• Hello, how are you? Are you keeping well?
• Good, thanks. How are you?
• “You just started your new job. How are you doing?”
• “I heard you just moved here. How are you doing?”
• “the report is due this Friday. How are you doing?”