Serif vs. Sans Serif
There is little, if any, significant difference in legibility between serif and sans serif fonts but some designers feel that serifs are easier to read—serifs create a series of dashes and dots which help carry the reader’s eye across the line of text and, therefore, make the text more legible. On the other hand, serif text can lose this linear effect if it is read on a computer screen—the serif may actually create noise which will reduce legibility. There is no steadfast rule regarding serifs but, generally, serif fonts are a good choice for printed material and sans serif is best read on a computer screen. See the below image for a comparison:
(Image taken from http://www.symplebyte.com/general_usage/fonts/serif_or_sans-serif.html)
For more information on fonts check out http://alexpoole.info/which-are-more-legible-serif-or-sans-serif-typefaces/
