there are 2 types of fonts that are widely used:
Serif Fonts - these are most widely used for PRINT media ie Times Roman, Georgia, but are not good for the Web, because they are difficult to read on the screen. Serif fonts are those that have fine cross-lines at the extremities of the letter.
Sans Serif Fonts - these are fonts that don't have serifs. They are the best fonts to use for the WEB (ie Verdana, Arial, Helvetica, Trebuchet) but are not appropriate for print media.