The link in the post to which you replied covers that; it's the section of the man page which deals specifically with differences between xargs and parallel. Ha

The link in the post to which you replied covers that; it's the section of the man page which deals specifically with differences between xargs and parallel. Having used neither of these tools before, I think two relevant lines from that link would be: >xargs can run a given number of jobs in parallel, but has no support for running number-of-cpu-cores jobs in parallel. >xargs has no support for keeping the order of the output, therefore if running jobs in parallel using xargs the output of the second job cannot be postponed till the first job is done.