There are several different type styles available in LaTeX: bold (bf), sans serif (sf), slanted (sl), SMALL CAPS (sc), typewriter (tt), italic (it), and the default, roman (rm). To use one of these type styles simply, use the appropriate command as shown in the following example.
The following lines: Are produced by:
This is bold type.
{\bf This is bold type.}This is sans serif type.
{\sf This is sans serif type.}This is slanted type.
{\sl This is slanted type.}THIS IS SMALL CAPS TYPE.
{\sc This is Small Caps type.}This is typewriter type.
{\tt This is typewriter type.}This is italic type.
{\it This is italic type.}This is normal roman type.
{\rm This is normal roman type.}
You will notice that there is no underline style. This is
intentional, since underlining is not normally used in a typeset
document. Titles (and other text normally underlined in hand-written
documents) are properly emphasized with the \em command.
If you really want to get , type
\underline{text to be underlined}, but note that
underlining is ``fragile'' (which makes it difficult to use in section
titles and a few other places--see the LaTeX manual for details).