kill Command

The kill command sends a signal to a process and kills the target process.

Syntax
kill -l List all known signal numbers, names, and descriptions.
kill Kill the controlled process.
kill job... Send the SIGTERM signal to the listed jobs.
kill -signal job... Send the given signal to the listed jobs.

where:

job may be a process ID or may be specified in any of the following ways:
%+ Kill the current job.
%- Kill the previous job.
%number Kill job number number.
%string Kill the job which begins with string.
%?string Kill the job which contains string.

signal is the name of a signal.