The two main font styles are:

SERIF fonts have extensions to the ends of strokes. Serif fonts are generally easier to read when set in small point sizes, for example, small text in newspapers tends to be Times Roman. Serif fonts tend to be considered as ‘old-fashioned'.

SANS SERIF fonts have strokes ending in a straight line. Sans serif fonts are considered easier to read when set in large point sizes, for example, in a presentation. Sans serif fonts are seen as being 'modern'. Because they want to be seen as modern, many websites use sans serif fonts such as Verdana, which is readable in small sizes on the screen.