When people in China want to write Chinese words using the English alphabet, they use a system called Chinese romanization. This means that instead of writing the characters that make up the word, they use English letters to represent the sounds of the word.
For example, the word "hello" in Chinese is "你好"。In Chinese romanization, this word is spelled "nǐ hǎo". See how the letters are different? That's because the sounds in Chinese don't always match up exactly with the sounds in English.
Chinese romanization can be very helpful for people who are learning Chinese or who need to communicate with people who don't speak Chinese. It allows them to write Chinese words using familiar letters and to pronounce them more accurately.
There are many different systems of Chinese romanization, but one of the most common is called Hanyu Pinyin. This system uses accents and special symbols to show exactly how each Chinese sound should be pronounced.
Overall, Chinese romanization is a way to write Chinese words using English letters, and it can be very useful for people who are learning or communicating in Chinese.