In writing and typography, a "serif" refers to the small decorative strokes or lines that are added to the ends of the main strokes of letters and symbols within a particular font. Serifs can vary in style, thickness, and shape, and they contribute to the overall aesthetic and readability of the text.
Fonts that feature serifs are called "serif fonts." They are often used in printed materials such as books and newspapers, as the serifs can help guide the reader's eye along lines of text. Some common examples of serif fonts include Times New Roman, Georgia, and Garamond.
In contrast, "sans-serif" fonts do not have these decorative strokes and tend to have a cleaner and more modern appearance. Examples of sans-serif fonts include Arial, Helvetica, and Verdana.
Choosing between serif and sans-serif fonts often depends on the context and purpose of the writing, as well as personal preference.