The two tapes of a transducer are typically viewed as an input tape and an output tape. On this view, a transducer is said to "transduce" (i.e., translate) the contents of its input tape to its output tape, by accepting a string on its input tape and generating another string on its output tape. It may do so nondeterministically and it may produce more than one output for each input string. A transducer may also produce no output for a given input string, in which case it is said to "reject" the input. In general, a transducer computes a relation between two formal languages.