|Style[expr,options]||print with the specified style options|
|Style[expr,"style"]||print with the specified cell style|
|FontSize||12||size of characters in printer's points|
|FontWeight||"Plain" or "Bold"||weight of characters|
|FontSlant||"Plain" or "Italic"||slant of characters|
|FontFamily||"Courier", "Times", "Helvetica"||font family|
|FontColor||GrayLevel||color of characters|
|Background||GrayLevel||background color for characters|
A few options that can be used in Style.
If you use the notebook front end for the Wolfram System, then each piece of output that is generated will by default be in the style of the cell in which the output appears. By using Style[expr,"style"], however, you can tell the Wolfram System to output a particular expression in a different style.
"Cells as Wolfram Language Expressions" describes in more detail how cell styles work. By using Style[expr,"style",options] you can generate output that is in a particular style, but with certain options modified.