Transliteration is the conversion of a text from one script to another.〔Kharusi, N. S. & Salman, A. (2011) The English Transliteration of Place Names in Oman. Journal of Academic and Applied Studies Vol. 1(3) September 2011, pp. 1–27 Available online at www.academians.org〕
For instance, a Latin transliteration of the Greek phrase "", usually translated as 'Hellenic Republic', is "".
Transliteration is not concerned with representing the sounds of the original, only the characters, ideally accurately and unambiguously. Thus, in the above example, λλ is transliterated as 'll', but pronounced /l/; Δ is transliterated as 'D', but pronounced 'ð'; and η is transliterated as 'ē', though it is pronounced /i/ (exactly like ι) and is not long.
Conversely, transcription notes the ''sounds'' but not necessarily the spelling. So "" could be transcribed as "", which does not specify which of the /i/ sounds are written as η and which as ι.
Systematic transliteration is a mapping from one system of writing into another, typically grapheme to grapheme. Most transliteration systems are one-to-one, so a reader who knows the system can reconstruct the original spelling.
Transliteration is opposed to transcription, which maps the ''sounds'' of one language into a writing system. Still, most systems of transliteration map the letters of the source script to letters pronounced similarly in the target script, for some specific pair of source and target language. If the relations between letters and sounds are similar in both languages, a transliteration may be very close to a transcription. In practice, there are some mixed transliteration/transcription systems that transliterate a part of the original script and transcribe the rest.
For many script pairs, there is one or more standard transliteration systems. However, unsystematic transliteration is common.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』