### \newcommand

 \newcommand{cmd}[args]{def}
\renewcommand{cmd}[args]{def}


These commands define (or redefine) a command.

cmd
args
An integer from 1 to 9 denoting the number of arguments of the command being defined. The default is for the command to have no arguments.
def
The text to be substituted for every occurrence of cmd; a parameter of the form #n in cmd is replaced by the text of the nth argument when this substitution takes place.