\raisebox command is used to raise or lower text. The first
mandatory argument specifies how high the text is to be raised (or
lowered if it is a negative amount). The text itself is processed in
Sometimes it's useful to make LaTeX think something has a different
size than it really does - or a different size than LaTeX would
normally think it has. The
\raisebox command lets you tell
LaTeX how tall it is.
The first optional argument,
extend-above, makes LaTeX think
that the text extends above the line by the amount specified. The
second optional argument,
extend-below, makes LaTeX think that
the text extends below the line by the amount specified.