In a non-interactive computer system, particularly IBM mainframes, a job stream, jobstream, or simply job is the sequence of job control language statements (JCL) and data (called instream data) that comprise a single "unit of work for an operating system". The term job traditionally means a one-off piece of work, and is contrasted with a batch (executing the same steps over many inputs), but non-interactive computation has come to be called "batch processing", and thus a unit of batch processing is often called a job, or by the oxymoronic term batch job; see job for details.