Complex sentence: In a batch processing computer system, 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".
Split into simpler sentences: In a batch processing computer system, 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 "job". A job is a single "unit of work for an operating system".