For Chinese, there is mandarin and Cantonese.
Mandarin sort of represents the words/pronounciation. Cantonese is the character that represents the pronunciation.
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In word or on any device
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For arabic
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TLDR:
- You type the mando (pronunciation) .. Using the typical english letters that you see on a keyboard..and then you can pick the character (canto) that corresponds to the pronunciation.
Such a system would exist for languages that have characters and letters too.
Languages like Chinese and Arabic literally have thousands of characters and/or letters. It would be impossible to have it all on a keyboard. You aren't ignorant at all =)
This is not at all the difference between Cantonese and Mandarin...they're different languages. Mandarin is the "official" language of China and is what people usually associate the word Chinese with, whereas Cantonese is spoken in Hong Kong and the surrounding province (Guangdong). In Australia, there is roughly equal numbers of Cantonese and Mandarin speakers, though most of the people our age who speak Chinese speak Mandarin.
The things that you've called Cantonese are characters and the English letters that you called Mandarin are called "pinyin". For thousands of years, Chinese speakers only wrote in characters; however, since the mid-20th century they started using pinyin to help them remember the pronunciation of the characters and, with the advent of computers, phones etc, to type. Pinyin is entirely phonetic, meaning that how it is written is exactly how it is pronounced.
When you type in Chinese, you can write in pinyin and see the characters pop up (just as above when you typed in nihao). You see different predictive options and can scroll through lists of characters with that pronunciation, if you click a particular button. This is particularly useful for names. Otherwise, there is also a keyboard that allows you to draw the character in. This is handy if you want to work out how the character is pronounced. You might read a character somewhere and not know how to say it, or its meaning, so you can just draw it into your phone. Another option is to use keyboards wherein you effectively type strokes. These keyboards are really tricky to explain, but they essentially involve typing in the brush strokes you'd use to write those characters by selecting from a relatively limited list of strokes. As with the pinyin and the drawing, you'll get various options.
Other languages, as Kate mentioned, tend to have their own organisations if they use Romanised letters. Typically these are essentially QWERTY with very minor moderations. The French keyboard (AZERTY) is the exception to this rule because, well, they're French. Otherwise the Spanish keyboard is the same as ours with the addition of ń.
Interestingly, languages with writing systems similar to ours but different (e.g. cyrillic, Greek) are arranged fairly similarly to QWERTY too. For instance, on a Russian keyboard, the letter б is in the same spot as b, which is the sound that letter makes. Likewise in Greek, you find β on B because the letter B is derived from it (when in fact beta actually sounds like v).