\parbox[position][height][inner-pos]{width}{text}
A parbox is a box whose contents are created in paragraph
mode. The \parbox has two mandatory arguments:
width - specifies the width of the parbox, and
text - the text that goes inside the parbox.
LaTeX will position a parbox so its centre lines up with the centre of
the text line. The optional position argument allows you
to line up either the top or bottom line in the parbox (default is top).
If the height argument is not given, the box will have the natural height of the text.
The inner-pos argument controls the placement of the text inside the box. If it is not specified, position is used.
t -- text is placed at the top of the box.
c -- text is centred in the box.
b -- text is placed at the bottom of the box.
s -- stretch vertically. The text must contain
vertically stretchable space for this to work.
A \parbox command is used for a parbox containing a small piece
of text, with nothing fancy inside. In particular, you shouldn't use
any of the paragraph-making environments inside a \parbox
argument. For larger pieces of text, including ones containing a
paragraph-making environment, you should use a minipage
environment See section minipage.