What's the difference between "had better" and "would rather"?

[أ/ أحمد البسيونى]

What's the difference between "had better" and "would rather"?
Had better is used to express what is advisable or a good idea to do:
I had better study hard.
You had better wash those apples before you eat them.

Had better can also be used as a mild threat.
Mother: You had better clean your room, young man.

Would rather expresses a preference, what you would like to do.

Would you rather have juice or a fizzy drink?

I had better study more, but I’d rather play football.