Transliteration is a type of conversion of a text from one script to another that involves swapping letters (thus trans- + liter-) in predictable ways, such as Greek ⟨α⟩ → ⟨a⟩, Cyrillic ⟨д⟩ → ⟨d⟩, Greek ⟨χ⟩ → the digraph ⟨ch⟩, Armenian ⟨ն⟩ → ⟨n⟩ or Latin ⟨æ⟩ → ⟨ae⟩.

For instance, for the Modern Greek term "Ελληνική Δημοκρατία", which is usually translated as "Hellenic Republic", the usual transliteration to Latin script is ⟨Ellēnikḗ Dēmokratía⟩, and the name for Russia in Cyrillic script, "Россия", is usually transliterated as ⟨Rossiya⟩.

Transliteration is not primarily concerned with representing the sounds of the original but rather with representing the characters, ideally accurately and unambiguously. Thus, in the Greek above example, ⟨λλ⟩ is transliterated ⟨ll⟩ though it is pronounced [l], ⟨Δ⟩ is transliterated ⟨D⟩ though pronounced [ð], and ⟨η⟩ is transliterated ⟨ē⟩, though it is pronounced [i] (exactly like ⟨ι⟩) and is not long.

Transcription, conversely, seeks to capture sound rather than spelling; "Ελληνική Δημοκρατία" corresponds to [elinicí ðimokratía] in the International Phonetic Alphabet. While differentiation is lost in the case of [i], note how the letter shape ⟨κ⟩ becomes either [c] or [k] depending on the vowel that follows it.

Angle brackets ⟨ ⟩ may be used to set off transliteration, as opposed to slashes / / for phonemic transcription and square brackets for phonetic transcription. Angle brackets may also be used to set off characters in the original script. Conventions and author preferences vary.