What's the main difference between "action" and "behavior"? Are they interchangeable?

Native speaker’s answer
Rebecca
An "action" is the act of doing something, whereas "behavior" is the way in which someone/something acts or conducts oneself. So there is a difference in meaning! However, the difference between these two is often not distinguished in casual speech, and "actions" and "behavior" are commonly interchangeably used. Ex: I hope you will think about your actions today. You hurt my feelings. (A specific act of doing something) Ex: My sister has behaved in a kind and considerate manner since she was a child. (The way of conducting oneself)