lightweight objects in the linux kernel that enable users
to partition their multiprocessor machine.
Multiprocessing is the use of two or more central
processing units (CPUs) within a single computer system
source : http://en.wikipedia.org/wiki/Multiprocessing
-j [jobs], --jobs[=jobs]
Specifies the number of jobs (commands) to run
simultaneously. If there is more than one -j option, the
last one is effective. If the -j option is given without
an argument, make will not limit the number of jobs that
can run simultaneously.
machines with multiple processors can attach network
programs of higher priorities to a processor that is
little consumed or idle.