"The 'niceness' of a process is a numeric hint to the kernel
about how the process should be treated in relation to other
processes contending for the CPU. The strange name is derived from
the fact that it determines how nice you are going to be to other
users of the system. A high nice value means a low priority for
your process: you are going to be nice. A low or negative value
means high priority: you are not very nice. The range of allowable
niceness values is -20 to +19.
"Unless the user takes special action, a newly created process
inherits the nice value of its parent process..."