Etymologically, "translation" is a "carrying across" or "bringing across." The Latin "translatio" derives from the perfectpassive participle, "translatum," of "transferre" ("to transfer" — from "trans," "across" + "ferre," "to carry" or "to bring"). The modern Romance, Germanic and Slavic European languages have generally formed their own equivalent terms for this concept after the Latin model — after "transferre" or after the kindred "traducere" ("to bring across" or "to lead across").
Additionally, the Greek term for "translation," "metaphrasis" ("a speaking across"), has supplied English with "metaphrase" (a "literal translation," or "word-for-word" translation)—as contrasted with "paraphrase" ("a saying in other words," from the Greek "paraphrasis"). "Metaphrase" corresponds, in one of the more recent terminologies, to "formal equivalence," and "paraphrase", to "dynamic equivalence."
Newcomers to translation sometimes proceed as if translation were an exact science — as if consistent, one-to-one correlations existed between the words and phrases of different languages, rendering translations fixed and identically reproducible, much as in cryptography. Such novices may assume that all that is needed to translate a text is to "encode" and "decode" equivalents between the two languages, using a translation dictionary as the "codebook."
On the contrary, such a fixed relationship would only exist were a new language synthesized and simultaneously matched to a pre-existing language's scopes of meaning, etymologies, and lexical ecological niches.  If the new language were subsequently to take on a life apart from such cryptographic use, each word would spontaneously begin to assume new shades of meaning and cast off previous associations, thereby vitiating any such artificial synchronization. Henceforth translation would require the disciplines described in this article.
Another common misconception is that anyonewho can speak a second language will make a good translator. In the translation community, it is generally accepted that the best translations are produced by persons who are translating into their own native languages, as it is rare for someone who has learned a second language to have total fluency in that language. A good translator understands the source language well, has specific experience in the subject matter of the text, and is a good writer in the target language. Moreover, he is not only bilingual but bicultural.
It has been debated whether translation is art or craft. Literary translators, such as Gregory Rabassa in If This Be Treason, argue that translation is an art – a teachable one. Other translators, mostly technical, commercial, and legal, regard their métier as a craft – again, a teachable one, subject to linguistic analysis, that benefits from academic study.
As with other human activities, the distinction between art and craft may be largely a matter of degree. Even a document which appears simple, e.g. a product brochure, requires a certain level of linguistic skill that goes beyond mere technical terminology. Any material used for marketing purposes reflects on the company that produces the product and the brochure. The best translations are obtained through the combined application of good technical-terminology skills and good writing skills.
Translation has served as a writing school for many prominent writers. Translators, including monks who spread Buddhist texts in East Asia and the early modern European translators of the Bible, in the course of their work have shaped the very languages into which they have translated. They have acted as bridges for conveying knowledge and ideas between cultures and civilizations. Along with ideas, they have imported, into their own languages, loanwords and calques of grammatical structures, idioms and vocabulary from the source languages.
Interpreting, or "interpretation," is the intellectual activity that consists of facilitating oral or sign-language communication, either simultaneously or consecutively, between two or among three or more speakers who are not speaking, or signing, the same language.
The words "interpreting" and "interpretation" both can be used to refer to this activity; the word "interpreting" is commonly used in the profession and in the translation-studies field to avoid confusion with other meanings of the word "interpretation."
Not all languages employ, as English does, two separate words to denote the activities of written and live-communication (oral or sign-language) translators. Even English does not always make the distinction, frequently using "translation" as a synonym of "interpretation", especially in nontechnical usage.
Fidelity vs. transparency
Fidelity (or "faithfulness") and transparency are two qualities that, for millennia, have been regarded as ideals to be striven for in translation, particularly literary translation. These two ideals are often at odds. Thus a 17th-century French critic coined the phrase, "les belles infidèles," to suggest that translations, like women, could be either faithful orbeautiful, but not both at the same time.
Fidelity pertains to the extent to which a translation accurately renders the meaning of the source text, without adding to or subtracting from it, without intensifying or weakening any part of the meaning, and otherwise without distorting it.
Transparency pertains to the extent to which a translation appears to a native speaker of the target language to have originally been written in that language, and conforms to the language's grammatical, syntactic and idiomatic conventions.
A translation that meets the first criterion is said to be a "faithful translation"; a translation that meets the second criterion, an "idiomatic translation." The two qualities are not necessarily mutually exclusive.
The criteria used to judge the faithfulness of a translation vary according to the subject, the precision of the original contents, the type, function and use of the text, its literary qualities, its social or historical context, and so forth.
The criteria for judging the transparency of a translation would appear more straightforward: an unidiomatic translation "sounds wrong," and in the extreme case of word-for-word translations generated by many machine-translation systems, often results in patent nonsense with only a humorous value (see "round-trip translation").
Nevertheless, in certain contexts a translator may consciously strive to produce a literal translation. Literary translators and translators of religious or historic texts often adhere as closely as possible to the source text. In doing so, they often deliberately stretch the boundaries of the target language to produce an unidiomatic text. Similarly, a literary translator may wish to adopt words or expressions from the source language in order to provide "local color" in the translation.
In recent decades, prominent advocates of such "non-transparent" translation have included the French scholar Antoine Berman, who identified twelve deforming tendencies inherent in most prose translations, and the American theorist Lawrence Venuti, who has called upon translators to apply "foreignizing" translation strategies instead of domesticating ones.
Many non-transparent-translation theories draw on concepts from German Romanticism, the most obvious influence on latter-day theories of "foreignization" being the German theologian and philosopher Friedrich Schleiermacher. In his seminal lecture "On the Different Methods of Translation" (1813) he distinguished between translation methods that move "the writer toward [the reader]," i.e., transparency, and those that move the "reader toward [the author]," i.e., an extreme fidelity to the foreignness of the source text. Schleiermacher clearly favored the latter approach. His preference was motivated, however, not so much by a desire to embrace the foreign, as by a nationalist desire to oppose France's cultural domination and to promote German literature.
For the most part, current Western practices in translation are dominated by the concepts of "fidelity" and "transparency." This has not always been the case. There have been periods, especially in pre-Classical Rome and in the 18th century, when many translators stepped beyond the bounds of translation proper into the realm of adaptation.
Adapted translation retains currency in some non-Western traditions. Thus the Indian epic, the Ramayana, appears in many versions in the various Indian languages, and the stories are different in each. If one considers the words used for translating into the Indian languages, whether those be Aryan or Dravidian languages, he is struck by the freedom that is granted to the translators. This may relate to a devotion to prophetic passages that strike a deep religious chord, or to a vocation to instruct unbelievers. Similar examples are to be found in medieval Christian literature, which adjusted the text to the customs and values of the audience.