Interpreting is a translational activity in which one produces a first
and final target-language output on the basis of a one-time exposure to
an expression in a source language. The most common two modes of
interpreting are simultaneous interpreting, which is done at the time of
the exposure to the source language, and consecutive interpreting, which
is done at breaks to this exposure. Interpreting is an ancient human
activity which predates the invention of writing. However, the origins
of the profession of interpreting date back to less than a century ago.