Styles and Fonts in Output
| Style[expr,options] | print with the specified style options |
| Style[expr,"style"] | print with the specified cell style |
Specifying output styles.
The second

is shown in boldface here.
| Out[1]= |  |
This shows the word

in font sizes from 10 to 20 points.
| Out[2]= |  |
This shows the text in the Helvetica font.
| Out[3]= |  |
Style allows an abbreviated form of some options. For options such as FontSize, FontWeight, FontSlant, and FontColor, you can include merely the setting of the option.
Options are specified here in a short form.
| Out[4]= |  |
A few options that can be used in Style.
If you use the notebook front end for Mathematica, 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 Mathematica to output a particular expression in a different style.
Here is an expression output in the style normally used for section headings.
| Out[5]= |  |
"Cells as Mathematica 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.