The noun for the act of writing a word in the letters of another writing system, and also for the result of doing that. It works in two ways, and both are common. First, uncountable, the process or practice: 'transliteration of Chinese names into English is not standardised', 'rules of transliteration'. Second, countable, the actual string of letters you end up with: 'Peking and Beijing are two transliterations of the same name', 'this is a transliteration, not a translation'. The important thing to hold on to is that a transliteration carries SOUND, not meaning. Someone reading it can pronounce the word but still has no idea what it means. That is why passports, maps, academic papers on Sanskrit, Greek or Arabic, and library catalogues all rely on it. Taiwanese students meet this constantly and personally: the Roman spelling of your own name is a transliteration, and because Taiwan has used several systems over the years — Wade-Giles, Tongyong pinyin, Hanyu pinyin — the same family can end up with Chang, Zhang and Chiang on different documents. Nothing is wrong; they are just different transliteration systems. The word is formal and belongs to writing and classroom talk; in daily speech people say 'the English spelling' or 'the pinyin'.