What's different
What's the difference? √
What's different 有什么变化（多指和以前做比较）
如果见到一个很久不见的朋友，我可能会说：“What's new?”
What's new? = What's happened since I last saw you?
我今天去理发了。你能看出来我头发有什么不同吗？
B：No, not really. What's the difference?
看不出来，有什么区别啊?
可口可乐和百事可乐有什么区别？
What's the difference between BB cream and Foundation? I literally have no idea.
BB和粉底有什么区别？我完全不知道。
