The question of fidelity vs. transparency has also been formulated in terms of, respectively, "formal equivalence" and "dynamic [or functional] equivalence". The latter expressions are associated with the translator Eugene Nida and were originally coined to describe ways of translating the Bible, but the two approaches are applicable to any translation.
"Formal equivalence" corresponds to "metaphrase", and "dynamic equivalence" to "paraphrase".
"Dynamic equivalence" (or "functional equivalence") conveys the essential thoughts expressed in a source text — if necessary, at the expense of literality, original sememe and word order, the source text's active vs. passive voice, etc.
By contrast, "formal equivalence" (sought via "literal" translation) attempts to render the text literally, or "word for word" (the latter expression being itself a word-for-word rendering of the classical Latin verbum pro verbo) — if necessary, at the expense of features natural to the target language.
There is, however, no sharp boundary between functional and formal equivalence. On the contrary, they represent a spectrum of translation approaches. Each is used at various times and in various contexts by the same translator, and at various points within the same text — sometimes simultaneously. Competent translation entails the judicious blending of functional and formal equivalents.
Common pitfalls in translation, especially when practiced by inexperienced translators, involve false equivalents such as "false friends" and false cognates.