You might’ve discovered that there are multiple ways to say “Chinese” in Chinese.
Let’s see how they differ and which one should you use.
Chinese (people)
| 中國人 | Person that holds a PRC nationality (he can ethnically be Chinese, but can also be Mongol, Uyghur, Hui and any other ethnic minority |
| 華人 | Person that is ethnically Chinese regardless of nationality |
| 漢人 | Person belonging to the Han ethnic group aka “Chinese” ethnic group, which practically makes it the same as 華人, but it’s used less often, and usually exclusively inside of mainland China |
| 台灣人，香港人，澳門人，新加坡人 | If you want to refer to people that are residents of a Chinese speaking nation outside of mainland China you can use a country specific demonym: 台灣人 – Taiwanese 香港人 – HKer 澳門人 – Macanese 新加坡人 – Singaporean |
| 華裔[country]人 | For ethnic Chinese holding a foreign passport you can use the 華裔[country]人 construction. For example America is 美國, so Chinese American is 華裔美國人 |
TL;DR: for PRC nationals use 中國人, for everyone else use 華人
Chinese (language)
| 中文 | Literally middle language. Technically it means written Chinese. But it is a general term to refer to Chinese language (written and spoken). |
| 漢語 | Literally “han language”. It’s often used in textbooks. Also it’s a general term, but in real speech it’s used a lot less often |
| 漢文 | Also “han language”. However, this terms is barely used, and when it is used it predominantly refers to Classical Chinese |
| 國語 | Literally “national language”, and it’s often used to refer to Mandarin Chinese in Taiwan. |
| 官話 | “Official language”, you’ll see this term very rarely and only in mainland China. But it also refers to Mandarin Chinese |
| 普通話 | “Common language” – spoken Mandarin Chinese (this term is only used in mainland China) |
| 中國話 | “Language of China” – refers to spoken Chinese. And it’s only used in China |
| 中國語 | “Language of China” – this is used only in Japanese. You won’t say it in Chinese. |
| 文言文 or 文言 |
Literal translation doesn’t really work for this one, but you’ll use 文言 to say “Classical Chinese language”. 文言 has been in active use until the 20th century, so you can find many poems written in it. |
| 白話 | “White language”- it’s the opposite of 文言. While 文言 is literary Chinese, 白話 is vernacular Chinese – the language of the ordinary people. Rarely used. |
| 廣東話，台灣話，客家話，上海話，etc | Aside from the aforementioned ways to say Chinese which you would mainly use for Mandarin there is a plethora of Chinese dialects, that have their own names (names are mostly derived from the names of the provinces/cities the dialects came from, ahem ahem …. 客家話). This wikipedia page can introduce you to all the dialects. |
TL;DR: just use 中文