However, do you know, actually there are a couple more greeting phrases in Chinese? Depending on the situation, different phrases should be used. Here I want to list some:
－－你好(nǐ hǎo) — Hello.
It is used in informal situations. It is used when addressing to one person. When used, no response is expected.
－－您好（nǐn hǎo) — Hello.
In formal situations, “您好” is used when addressing an elder person or a person at a higher rank.
－－你们好(nǐ mén hǎo ) — Hello.
This can be used in both formal and informal situations. It is used when addressing a group of people.
Sometimes you may hear “你好吗？” (nǐ hǎo mā?) which is a greeting question instead of a greeting, so an answer is expected. A typical answer is “我很好，谢谢，你呢？“ In detail,
－－你好吗？(nǐ hǎo mā?) — How are you doing?
—我很好，谢谢。你呢？（wǒ hěn hǎo. xiè xiè. nǐ nē?) — I am very well. Thank you. And you?
I hope it would be helpful to understand the difference.