Why don't you use a dictionary?

Here are some examples for you. The word INFORM is often used when speaking about general information. A teacher, for example, will inform the class about the topics that will be covered during the school year. The word NOTIFY is often used when speaking about RULES, REQUIREMENTS and REGULATIONS. The teacher would notify the class that essays must be completed by the end of the month. The word WARN is used when speaking about serious dangers or consequences. The same teacher would warn the student who has missed weeks of classes that he will be expelled. Hope this helps.

杨某不胜感激各位的回答 ！😃

Notify = to inform someone about a particular information Warn = there is some danger or risks involved. Alert someone about this danger or risk.

notify让你看到注意到接收到，inform通知，warn警告