Translation is the comprehension of the meaning of a text and the subsequent production of an equivalent text, likewise called a «translation,» that communicates the same message in another language. The text to be translated is called the source text, and the language that it is to be translated into is called the target language; the final product is sometimes called the target text.
Translation, when practiced by relatively bilingual individuals but especially when by persons with limited proficiency in one or both languages, involves a risk of spilling-over of idioms and usages from the source language into the target language. On the other hand, inter-linguistic spillages have also served the useful purpose of importing calques and loanwords from a source language into a target language that had previously lacked a concept or a convenient expression for the concept. Translators and interpreters, professional as well as amateur, have thus played an important role in the evolution of languages and cultures.
The art of translation is as old as written literature. Parts of the Sumerian Epic of Gilgamesh, among the oldest known literary works, have been found in translations into several Southwest Asian languages of the second millennium BCE. The Epic of Gilgamesh may have been read, in their own languages, by early authors of the Bible and of the Iliad.
Since the Industrial Revolution, developments in technology, communications and business have changed translation greatly. Once the activity of a relatively small group of clerics, scholars and wealthy amateurs working with religious or literary texts, it is now a profession with accredited schools, professional associations, and accepted standards and payscales. In particular, the advent of the Internet has greatly expanded the market for translation and introduced a vast array of new tools and types of work, including product localization, content management, and multilingual documentation. An estimated 75% of professional translators currently make their living from technical texts of various kinds.
Since the 1940s, attempts have been made to computerize or otherwise automate the translation of natural-language texts (machine translation) or to use computers as an aid to translation (computer-assisted translation).