how are you?An informal way to ask someone how they are or how something is going. เป็นไง is a shortened form of เป็นอย่างไร; บ้าง adds the sense of “how is it going?” or “how are things?”
how is it?An informal conversational way to ask how someone or something is, or how something went. เป็นไง is a shortened form of เป็นอย่างไร, and the phrase can be used for people, situations, results, or appearances.