Typefaces can be divided into two main categories: serif and sans serif. Serifs comprise the small features at the end of strokes within letters. The printing industry refers to typeface without serifs as sans serif (from French sans, meaning without), or as grotesque (or, in German, grotesk).
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 serifs forms is only one of many factors to consider when choosing a typeface.
Typefaces with serifs are often considered easier to read in long passages than those without. Studies on the 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.