\sbox{cmd}{text}
\savebox{cmd}[width][pos]{text}
These commands typeset text
in a box just as for
\mbox
or
\makebox
.
However, instead of printing the resulting box, they save it in
the LaTeX command
cmd
, which must have been declared with
\newsavebox
.
The saved text
is accessed by a
\usebox
command.
The \sbox
and \savebox
commands are
declarations with the usual
rules for scope.
The \sbox
command is robust;
the \savebox
command is fragile.