Typefaces can be divided into two main categories: Serif and Sans serif. Serifs are semi-structural details on the ends of some of the strokes that make up letters and symbols. The printing industry refers to typeface without serifs as sans serif (from French sans, meaning without).
Ancient wisdom tells us that we should use sans-serif fonts for titles, headers, and other short blocks of text, and serif fonts for the main body of the document. The reasoning behind this has to do with the purpose of the serifs. The serifs on the letters are designed to pull the text together, making it easier for your eye to transition from one letter to the next, then from one word to the next. In effect, the serifs ‘pull’ you through the document, and in doing so make the text easier to read. Therefore, long blocks of text will be easier to read if they are written with a serif font. Sans-serif fonts work well in short blocks of larger text, what you would typically find in titles and headings.
Great variety exists among both serif and sans serif typefaces. Both groups contain faces designed for setting large amounts of body text, and others intended primarily as decorative. The presence or absence of serif forms is only one of the many factors to consider when choosing a typeface.
In traditional printing, serif fonts are used for body text because they are considered easier to read than sans-serif fonts and thus are the primary choice for lengthy text printed in books, newspapers and magazines. Sans-serif fonts are more often used in headlines, headings, and shorter pieces of text and subject matter requiring a more casual feel than the formal look of serifed types.
Typefaces with serifs are often considered easier to read in long passages than those without. However, studies on this matter are ambiguous, suggesting that most of this effect is due to the greater familiarity of serif typefaces. As a general rule, printed works such as newspapers and books almost always use serif typefaces, at least for the text body. Web sites do not have to specify a font and can simply respect the browser settings of the user. But of those web sites that do specify a font, most use modern sans serif fonts, because it is commonly believed that, in contrast to the case for printed material, sans serif fonts are easier than serif fonts to read on the low-resolution computer screen.
Serif fonts can be broadly classified in one of four groups:
Examples of old style typefaces include Garamond, Goudy Old Style, and Palatino.
Common examples include Bodoni, Didot, and Computer Modern.
They are among the most common, including such widespread typefaces as Times New Roman and Baskerville.
Examples of slab serif typefaces include Clarendon, Rockwell and Courier.
Sans Serif fonts can be classified in one of four groups:
A few examples are Akzidenz Grotesk, and Franklin Gothic.
Examples include modern designs such as MS Sans Serif, Helvetica, Univers and Arial.
A few examples include Calibri, Lucida Grande, Segoe UI, Myriad, Frutiger, Tahoma and Verdana.
A few examples are Futura, ITC Avant Garde, and Century Gothic.
So what does this mean to you? Well, it always seems to come back to the primary purpose of the document. If you are creating something whose primary purpose is to be printed on paper, then the typical sans serif for titles and headers, serif for the body of the text is probably best. However, if you’re creating something that will primarily be viewed on the computer, you are probably better off sticking with a sans-serif font for everything.