Parallelism, or parallelization, or parallel computing, means making use of multiple processors to complete a task more quickly than on a single processor.
For using multiple threads when the presence of more than one processor is irrelevant, use multithreading or concurrency instead. For parallelism over multiple machines, and not just over multiple processors in the same machine, use cluster in addition to or instead of this tag.
gnu-parallel is a common tool for parallel execution.
Useful links
- Parallel execution of a program on multiple files
- Four tasks in parallel... how do I do that?
- Poor Man's GNU Parallel implemented in ksh?